INTERNET-DRAFT
R. deBry
IBM Corporation
T. Hastings
Xerox Corporation
R. Herriot
Sun Microsystems
S. Isaacson
Novell, Inc.
P. Powell
San Diego State University
June 3, 1997
Internet Printing Protocol/1.0: Model and Semantics
draft-ietf-ipp-model-01.txt
Status of this Memo
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ftp.isi.edu (US West Coast).
Abstract
This document is one of a set of documents, which together describe all
aspects of a new Internet Printing Protocol (IPP). IPP is an
application level protocol that can be used for distributed printing
using Internet tools and technology. The protocol is heavily influenced
by the printing model introduced in the Document Printing Application
(ISO/IEC 10175 DPA) standard. Although DPA specifies both end user and
administrative features, IPP version 1.0 is focused only on end user
functionality.
The full set of IPP documents includes:
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Internet Printing Protocol: Requirements
Internet Printing Protocol/1.0: Model and Semantics
Internet Printing Protocol/1.0: Security
Internet Printing Protocol/1.0: Protocol Specification
Internet Printing Protocol/1.0: Directory Schema
The requirements document takes a broad look at distributed printing
functionality, and it enumerates real-life scenarios that help to
clarify the features that need to be included in a printing protocol for
the Internet. It identifies requirements for three types of users: end
users, operators, and administrators. The requirements document calls
out a subset of end user requirements that must be satisfied in the
first version of IPP. Operator and administrator requirements are out
of scope for v1.0. The model and semantics document describes a
simplified model with abstract objects, their attributes, and their
operations. The model introduces a Printer object and a Job object. The
Job object supports multiple documents per job. The security document
covers potential threats and proposed counters to those threats. The
protocol specification is formal document which incorporates the ideas
in all the other documents into a concrete mapping using clearly defined
data representations and transport protocol mappings that real
implementers can use to develop interoperable client and server side
components. Finally, the directory schema document shows a generic
schema for directory service entries that represent instances of IPP
Printers.
This document is the "Internet Printing Protocol/1.0: Model and
Semantics" document.
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Table of Contents
1. 6
Introduction..........................................................7
2. Terminology........................................................7
2.1 Conformance Terminology........................................8
2.1.1 MUST......................................................8
2.1.2 MUST NOT..................................................8
2.1.3 SHOULD....................................................8
2.1.4 SHOULD NOT................................................8
2.1.5 MAY.......................................................8
2.1.6 CONDITIONALLY MANDATORY...................................8
2.1.7 NEED NOT..................................................9
2.2 Model Terminology..............................................9
2.2.1 Keyword...................................................9
2.2.2 Attributes................................................9
2.2.3 Attribute Name............................................9
2.2.4 Group Name................................................9
2.2.5 Attribute Value..........................................10
2.2.6 Attribute Syntax.........................................10
2.2.7 Implements...............................................10
2.2.8 Supports.................................................10
3. Simplified Printing Model.........................................11
4. IPP Objects.......................................................13
4.1 Printer Object................................................13
4.2 Job Object....................................................15
4.3 Document Object...............................................16
4.4 Object Relationships..........................................17
4.5 Object Attributes.............................................17
4.5.1 Job Template Attribute Overview..........................17
4.5.2 The "best-effort" Job Attribute Overview.................18
4.6 Object Identity...............................................19
5. IPP Operations....................................................19
5.1 Operation Semantics...........................................20
5.1.1 Print-Job Operation......................................20
5.1.1.1 Print-Job Request...................................20
5.1.1.2 Print-Job Response..................................22
5.1.2 Create-Job Operation.....................................23
5.1.2.1 Create-Job Request..................................23
5.1.2.2 Create Job Response.................................24
5.1.3 Send-Document Operation..................................25
5.1.3.1 Send-Document Request...............................25
5.1.3.2 Send-Document Response..............................25
5.1.4 Cancel Job Operation.....................................26
5.1.4.1 Cancel-Job Request..................................26
5.1.4.2 Cancel-Job Response.................................26
5.1.5 Get-Attributes Operation.................................26
5.1.5.1 Get-Attributes Request..............................27
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5.1.5.2 Get-Attributes Response.............................28
5.1.6 Get-Jobs Operation.......................................29
5.1.6.1 Get-Jobs Request....................................29
5.1.6.2 Get-Jobs Response...................................30
5.2 Operation Status and Messages.................................31
5.3 Status Codes (type2 keyword)..................................31
6. Object Attributes.................................................31
6.1 Attribute Syntaxes............................................32
6.1.1 Attribute Extensibility..................................35
6.2 Job Template Attributes.......................................36
6.2.1 job-name (name)..........................................41
6.2.2 job-sheets (type4 keyword)...............................42
6.2.3 notification-events (1setOf type2 keyword)...............42
6.2.4 notification-addresses (1setOf uri)......................42
6.2.5 job-priority (integer(1:100))............................43
6.2.6 job-hold-until (type4 keyword)...........................43
6.2.7 multiple-documents-are (type2 keyword)...................44
6.2.8 best-effort (type2 keyword)..............................44
6.2.9 media (type4 keyword)....................................45
6.2.10 number-up (type3 keyword)...............................46
6.2.11 sides (type2 keyword)...................................46
6.2.12 printer-resolution (type2 keyword)......................47
6.2.13 print-quality (type2 keyword)...........................47
6.2.14 copies (integer(1:2**31 - 1))...........................48
6.2.15 finishings (1setOf type2 keyword).......................48
6.2.16 compression (type3 keyword).............................48
6.2.17 job-k-octets (integer(0:2**31 - 1)).....................48
6.2.18 job-impressions (integer(0:2**31 - 1))..................49
6.2.19 job- media-sheets (integer(0:2**31 - 1))................49
6.3 Job Attributes................................................49
6.3.1 Job Template Attributes..................................49
6.3.2 Job Description Attributes...............................49
6.3.2.1 job-URI (uri).......................................51
6.3.2.2 job-originating-user (name).........................51
6.3.2.3 job-originating-host (name).........................51
6.3.2.4 user-locale (type3 keyword).........................51
6.3.2.5 job-state (type1 keyword)...........................51
6.3.2.6 job-state-reasons (1setOf type2 keyword)...........55
6.3.2.7 job-state-message (text)............................58
6.3.2.8 output-device-assigned (uri)........................58
6.3.2.9 time-since-submission (milliseconds)................58
6.3.2.10 time-since-processing (milliseconds)...............58
6.3.2.11 number-of-intervening-jobs (integer(0:2**31 - 1))..58
6.3.2.12 job-message-from-operator (text)...................59
6.3.2.13 time-since-completion (milliseconds)...............59
6.3.2.14 job-k-octets-completed (integer(0:2**31 - 1))......59
6.3.2.15 job-impressions-completed (integer(0:2**31 - 1))..59
6.3.2.16 job-media-sheets-completed (integer(0:2**31 - 1))..59
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6.4 Document Attributes...........................................59
6.4.1 document-name(name, Mandatory)...........................60
6.4.2 document-format (type2 keyword)..........................60
6.4.3 document-URI (uri).......................................61
6.5 Printer Attributes............................................61
6.5.1 Printer Job Template Attributes..........................61
6.5.2 Printer Description Attributes..........................61
6.5.2.1 printer-URI (uri)...................................63
6.5.2.2 printer-name (name).................................63
6.5.2.3 printer-location (text).............................63
6.5.2.4 printer-description (text)..........................63
6.5.2.5 printer-more-info-site (uri)........................64
6.5.2.6 printer-driver-installer (uri)......................64
6.5.2.7 printer-make-and-model (text).......................64
6.5.2.8 maximum-printer-speed (integerUnits)................64
6.5.2.9 printer-more-info-manf (uri)........................64
6.5.2.10 printer-state (type1 keyword)......................65
6.5.2.11 printer-state-reasons (1setOf type2 keyword).......67
6.5.2.12 printer-is-accepting-jobs (boolean)................69
6.5.2.13 printer-state-message (text).......................69
6.5.2.14 queued-job-count (integer(0:2**31 - 1))............70
6.5.2.15 printer-message-from-the-operator (text)...........70
6.5.2.16 printer-locale (locale)............................70
6.5.2.17 printer-locales-supported (1setOf locale)..........70
7. Conformance.......................................................70
7.1 Conditionally Mandatory.......................................70
7.2 Client Conformance Requirements...............................71
7.3 Printer Object Conformance Requirements.......................71
7.3.1 Objects..................................................71
7.3.2 Operations...............................................71
7.3.3 Attributes...............................................72
7.3.4 Default Value............................................72
7.3.5 Availability.............................................73
7.3.6 Printer extensions.......................................73
7.3.7 Attribute Syntaxes.......................................73
7.4 Security Conformance Requirements.............................73
8. IANA Considerations, Registered Extensions, Private Extensions....73
9. Security Considerations...........................................74
10. References.......................................................74
11. Author's Address.................................................75
12.77
Change History.......................................................78
12.1 Changes made to version 970512, dated 12-May-1997 to make
version 970603, dated 03-June-1997...............................78
12.2 Changes made to version 970509, dated 9-May-1997 to make version
970512, dated 12-May-1997.........................................78
12.3 Changes made to version 2.2, dated 5-May-1997 to make version
970509, dated 9-May-1997..........................................79
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12.4 Changes made to version 2.1, dated 24-April-1997 to make version
2.2, dated 5-May-1997.............................................79
12.5 Changes made to version 2.0, dated 26-March-1997 to make version
2.1, dated 22-April-1997..........................................79
12.6 Changes made to version 1.8, dated 24-March-1997 to make version
2.0, dated 26-March-1997..........................................79
12.7 Changes made to version 1.7, dated 24-Mar-1997 to make version
1.8, dated 24-March-1997..........................................79
12.8 Changes made to version 1.6, dated 12-Mar-1997 to make version
1.7, dated 24-March-1997..........................................80
12.9 Changes made to version 1.5, dated 11-Mar-1997 to make version
1.6, dated 12-March-1997..........................................80
12.10 Changes made to version 1.4, dated 27-Feb-1997 to make version
1.5, dated 9-March-1997...........................................82
1.
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Introduction
The Internet Printing Protocol (IPP) is an application level protocol
that can be used for distributed printing on the Internet. The protocol
is heavily influenced by the printing model introduced in the Document
Printing Application (ISO/IEC 10175 DPA) standard. Although DPA
identifies both end user and administrative features, the first version
of IPP is focused only on end user functionality.
Section 2. Terminology introduces the terminology used within this
document.
Section 0 introduces the simplified IPP model. The IPP model is made
simple by exposing only the objects, attributes, and operations that are
essential for end user access and control of the print subsystem. When
future versions of IPP include features which satisfy operator and
administrator requirements, the model can be extended to support the
appropriate objects, attributes, and operations.
Section 0 introduces the full semantics of the Printer, Job, and
Document objects in the IPP model. It covers how instances of these
objects are identified, named, and related to each other.
Section 0 covers the operations that are part of the IPP model. These
operations include: the Create-Job, Send-Document, Print-Job, Cancel,
Get-Attributes, and Get-Jobs operations.
Section 0 describes the attributes, their syntaxes, and semantics which
are part of the IPP model. Each object's attributes are described, and
the attributes are grouped into logical groups to help clarify their
relationships and meaning. These groups are also used to simplify
queries that request multiple attributes.
Section 7. Conformance is a review of conformance issues and clarifies
requirements that apply to client side and server side implementations.
Sections 8. IANA Considerations, Registered Extensions, Private
Extensions-11. Author's Address cover extensibility, security, technical
references, and author information.
2. Terminology
This specification uses the terminology defined in this section.
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2.1 Conformance Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [25].
2.1.1 MUST
This word, or the terms "REQUIRED", "SHALL" or "MANDATORY", mean that
the definition is an absolute requirement of the specification.
2.1.2 MUST NOT
This phrase, or the phrase "SHALL NOT", mean that the definition is an
absolute prohibition of the specification.
2.1.3 SHOULD
This word, or the adjective "RECOMMENDED", mean that there may exist
valid reasons in particular circumstances to ignore a particular item,
but the full implications must be understood and carefully weighed
before choosing a different course.
2.1.4 SHOULD NOT
This phrase, or the phrase "NOT RECOMMENDED" mean that there may exist
valid reasons in particular circumstances when the particular behavior
is acceptable or even useful, but the full implications should be
understood and the case carefully weighed before implementing any
behavior described with this label.
2.1.5 MAY
This word, or the adjective "OPTIONAL", mean that an item is truly
optional. One vendor may choose to include the item because a
particular marketplace requires it or because the vendor feels that it
enhances the product while another vendor may omit the same item. An
implementation which does not include a particular option MUST be
prepared to interoperate with another implementation which does include
the option, though perhaps with reduced functionality. In the same vein
an implementation which does include a particular option MUST be
prepared to interoperate with another implementation which does not
include the option (except, of course, for the feature the option
provides.)
2.1.6 CONDITIONALLY MANDATORY
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This term means that an item MUST be implemented in a conforming
implementation if the item corresponds to a feature or behavior that the
implementation is capable of realizing. It is also true, that a
conforming implementation NEED NOT implement the items that correspond
to features or behaviors that the implmentation is not capable of
realizing.
2.1.7 NEED NOT
The verb "NEED NOT" indicates an action that the subject of the sentence
does not have to implement in order to claim conformance to the
standard. The verb "NEED NOT" is used instead of "MAY NOT" since "MAY
NOT" sounds like a prohibition.
2.2 Model Terminology
2.2.1 Keyword
Keywords are used within this document as identifiers of semantic
entities within the abstract model. These entities are often attribute
names, attribute values, attribute syntaxes, and attribute groups. In
this document, a keyword is a sequence of characters (length of 1 to
255) which consists of the following ASCII characters: letters, digits,
hyphen ("-"), and underscore ("_"). A keyword MUST start with a letter.
In the actual protocol, these keywords will be represented using an
appropriate protocol encoding (strings, enumerated values, constants,
operation codes, identifiers, etc.).
2.2.2 Attributes
An attribute is an item of information consisting of an attribute name
and attribute value(s) using a specific syntax for that attribute. All
attributes are defined in section 6. Object Attributes. Attributes
are identified as being "MANDATORY", "CONDITIONALLY MANDATORY", or
"OPTIONAL".
2.2.3 Attribute Name
Each attribute is uniquely identified in this document by its attribute
name which is a keyword. The keyword attribute name is given in the
section header describing that attribute. In running text in this
document, attribute names are indicated inside double quotation marks
(").
2.2.4 Group Name
Related attributes are grouped into named groups. The name of the group
is a keyword. It can be used wherever an attribute name is used in
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place of naming all the attributes in the group explicitly. Attribute
groups are defined in section 6. Object Attributes.
2.2.5 Attribute Value
Each attribute shall have one or more values. Attribute values shall be
represented in the syntax type specified for that attribute. In running
text in this document, attribute values are indicated inside single
quotation marks ('), whether their syntax types are keyword, integer,
text, etc.
2.2.6 Attribute Syntax
Each attribute is defined using an explicit syntax. In this document,
each syntax type is defined as a keyword with specific meaning. The
protocol specification document [23] shall indicate the actual
representation for each syntax type that shall be used for the actual
protocol. Attribute syntaxes are defined in section 6.1 Attribute
Syntaxes.
2.2.7 Implements
By definition, an attribute is implemented if, in response to a query
for that attribute, an implementation responds with both the attribute
and a current value (or values) for that attribute. . A conforming
implementation SHALL implement all MANDATORY attributes and it SHALL
implement all CONDITIONALLY MANDATORY attributes whose possible values
correspond to the behaviors that the implementation is capable of
realizing.
2.2.8 Supports
By definition, a job processing behavior or selectable feature is
supported by Printer only if that Printer implements the corresponding
"supported" attribute populated with the value representing that
behavior or feature. A given implementation may exhibit a behavior that
corresponds to the value of some supported attribute, but if the
implementation, when queried for that attribute, doesn't respond with
the supported attribute populated with that specific value, then as far
as IPP is concerned, that Printer does not support that feature.
Section 6. Object Attributes describes all of the Printer object's
supported attributes. Most of the Printer object's supported attributes
are OPTIONAL or CONDITIONALLY MANDATORY, therefore conformance to IPP
does not mandate that all implementations support all possible value
representing all possible job processing behaviors and features.
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For example, if a given instance of a Printer supports only certain
document formats, then that Printer SHALL implement the "document-
format-supported" attribute and that attribute SHALL be populated with a
set of values, possibly only one, taken from the entire set of possible
values defined in this model document. This implemented set of values
represent the Printer's set of supported document formats. Another
example is the "finishings-supported" attribute. If a Printer is not
physically capable of stapling (there is no stapler in the output device
itself), the "finishings-supported" attribute MUST NOT be implemented
with the value of 'staple'. Note: The supported attributes are set
(populated) by some administrative process or automatic sensing
mechanism which is outside the scope of IPP.
3. Simplified Printing Model
In order to a achieve its goal of realizing a workable printing protocol
for the Internet, IPP is based on a simplified printing model which
abstracts the many (often complex) components of real world printing
solutions. Many of these systems include features, interfaces, and
relationships that are beyond the scope of IPP. IPP has to run in a
distributed computing environment where requesters of print services
(clients, applications, PC drivers, etc.) cooperate and interact with
print service providers. Although the underlying configuration may be a
complex n-tier client/server system, an important simplifying step in
the IPP model is to expose only the key objects and interfaces required
for printing. The IPP model encapsulates these important elements into
three simple objects:
Printer (Section 0)
Job (Section 0)
Document (Section 0)
Each of these objects has a set of operations associated with it. These
include:
Printer:
Create-Job (Section 0)
Print-Job (Section ???)
Get-Attributes (Section 0)
Get-Jobs (Section 0)
Job
Send-Document(section ???)
Get-Attributes (Section 0)
Cancel Job (Section 0)
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There are no operations defined for a Document object. All document
information is accessed through a Job object and its operations.
It is important, however, to understand that in real system
implementations (which lie underneath the abstracted IPP model), there
are other components of a print service which are not explicitly defined
in the IPP model. The following figure illustrates where IPP fits with
respect to these other components.
+--------------+
| Application |
o +. . . . . . . |
\|/ | Spooler |
/ \ +. . . . . . . | +---------+
End-User | Print Driver |---| File |
+-----------+ +-----+ +------+-------+ +----+----+
| Browser | | GUI | | |
+-----+-----+ +--+--+ | |
| | | |
| +---+------------+---+ |
N D S | | IPP Client |------------+
O I E | +---------+----------+
T R C | |
I E U |
F C R -------------- Transport ------------------
I T I
C O T | --+
A R Y +--------+--------+ |
T Y | IPP Server | |
I +--------+--------+ |
O | |
N +.................+ | IPP Printer
| Print Service | |
+.................+ |
| |
Output Device(s) |
--+
IPP Printers encapsulate the functions normally associated with physical
output devices along with the spooling, scheduling and multiple device
management functions associated with a print server. Printers may be
registered as entries in a directory where end users find and select
them based on some sort of filtered and context based searching. The
directory is used to store relatively static information about the
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Printer, allowing end users to search for and find Printers that match
their search criteria (name, context, printer capabilities, etc.)
IPP clients implement the IPP protocol on the client side and give end
users or programs the ability to query an IPP Printer and submit and
manage their print jobs. An IPP server is just that part of the IPP
Printer that implements the protocol. The rest of the IPP Printer
implements the application semantics of the print service itself. All
information about the Printer, both static and dynamic information, can
be accessed directly from the Printer itself. The more dynamic
information associated with a Printer includes state, currently loaded
and ready media, number of jobs on the Printer, errors, warnings, etc..
When a job is submitted to the Printer, a Job object is created. The
end user then interacts with this new Job to query its status and
monitor the progress of the job. End users may also cancel the Job.
The end user is able to register to receive certain events which are
then routed using the notification service(s).
4. IPP Objects
4.1 Printer Object
A major component of the IPP model is the Printer object.
The capabilities and state of an IPP Printer are described by its
attributes. Printer attributes are defined in the following categories:
Job Template Attributes (section 6.5.1 Printer Job Template
Attributes)
Printer Description Attributes (section 6.5.2 Printer Description
Attributes)
Operations which are invoked on a printer include:
Create-Job (section 0)
Print-Job (section ???)
Get-Attributes (section 0)
Get-Jobs (section 0)
An instance of a Printer object implements IPP. Using the protocol, end
users may query the attributes of the Printer, submit jobs to the
Printer, determine subsequent states of submitted and queued jobs, and
cancel their own print jobs. The realization of a Printer object may
take on different forms for any given configuration of real components.
However, the details of the configuration of real components must be
transparent to the end user.
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Since a Printer object is an abstraction of a generic document output
device or print service provider, an IPP Printer object could be used to
represent any real or virtual device with semantics consistent with the
Printer object. For example, an instance of a Printer object could be
used to front end a fax-out device, any kind of imager, or even a CD
writer.
Some examples of configurations supporting a Printer object include:
1) An output device, with no spooling capabilities
2) An output device, with a built-in spooler
3) A print server supporting IPP with one or more associated output
devices
3a) The associated output devices might or might not be capable of
spooling jobs
3b) The associated output devices might or might not support IPP
See the following figures for some examples on how to view Printer
objects on top of several print system configurations. The embedded
case below represents configurations 1 and 2. The hosted and fan-out
figures below represent configuration 3.
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Legend:
##### indicates a Printer object which is
either embedded in an output device or is
hosted in a server. The implementation
might or might not be capable of queuing/spooling.
any indicates any network protocol or direct
connect, including IPP
embedded printer:
output device
+---------------+
O +--------+ | ########### |
/|\ | client |------------IPP------------># Printer # |
/ \ +--------+ | # Object # |
| ########### |
+---------------+
hosted printer:
+---------------+
O +--------+ ########### | |
/|\ | client |--IPP--># Printer #-any->| output device |
/ \ +--------+ # Object # | |
########### +---------------+
+---------------+
fan out: | |
+-->| output device |
any/ | |
O +--------+ ########### / +---------------+
/|\ | client |-IPP-># Printer #--*
/ \ +--------+ # Object # \ +---------------+
########### any\ | |
+-->| output device |
| |
+---------------+
4.2 Job Object
A Job object is used to model a job. A job can contain one or more
documents. The information required to create a Job object is sent in a
create request from the end user via an IPP client to a Printer. A
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create request can be either a Create-Job Request or a Print-Job
Request. The Printer may perform some validation checks to verify that
the job may indeed be processed. For example, the create request may
specify that the documents within the job are to be printed duplex (on
both sides of the media). However, the Printer might not support such a
feature. Once the Printer validates the submitted information, a Job
object is created. The instance of the Job object is initialized with
information from the create request. If a Create-Job operation is used
to create the Job object, subsequent Send-Document operations are used
to transfer the document data from the client to the IPP Printer.
This model specification defines rules for what MUST be done when:
- optional attributes are missing
- there are conflicts between what is supported and what is
requested
- there are conflicts between what the client requests via external
attributes in the IPP operation and what the client requests in
embedded instructions in the document page description language
(PDL).
Job attributes are broken up into the following groups:
Job Template Attributes (optionally supplied by the client/end user,
section 6.3.1 Job Template Attributes
Job Description Attributes (set by the Printer, section 6.3.2 Job
Description Attributes)
The following operations can be invoked on Jobs:
Send-Document(section 5.1.3 Send-Document Operation)
Cancel Job (section 0)
Get-Attributes (section 0)
4.3 Document Object
Documents consist of printable data and attributes that describe the
data to be printed. In this version of the protocol only the attributes
in section 6.4 Document Attributes are defined for individual
documents. Documents are sent in a Send-Document operation or in a
Print-Job operation.
Document attributes include:
Document Attributes (section 0)
Currently no operations are defined on documents.
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4.4 Object Relationships
Instances of objects within the system have relationships that must be
maintained persistently along with the persistent storage of the object
attributes. A Printer can represent one or more output devices. An
output device can be represented by at most one Printer object. A
Printer can contain zero or more Job objects. A Job object is contained
in exactly one Printer object. A Job object contains one or more
Documents. If the Document is simply a reference to some print data
stream, the reference may be used in multiple documents in the same Job
or even in different Jobs. If the Document is not just a reference, but
an actual stream of print data, it shall only be contained in one
Document, although there can be copies of it in other Documents.
4.5 Object Attributes
Each object type is defined by a set of attributes which describe the
realization of each instance of an object. That is, a Printer object is
defined as set of attributes that are associated with each instance of a
Printer object. In the same manner, a Job object is defined by defining
the set of attributes that are associated with each instance of a Job
object. Some attributes are OPTIONAL, some are MANDATORY, and some are
CONDITIONALLY MANDATORY (see section 2). Object attributes are defined
in section 0 of this document.
4.5.1 Job Template Attribute Overview
Attributes that a client may optionally include in a create request are
called Job Template attributes. These are described in detail in
section 0. The Printer object has associated attributes which define
supported and default values for the Printer.
- When a Job Template attribute is supplied by a client in a create
request, the attribute and its value describe the desired job
processing behavior.
- The Printer object's supported attribute describes what behaviors
are possible.
- The Printer object's default value attribute describes what will be
done when no other job processing information is supplied by the
client.
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4.5.2 The "best-effort" Job Attribute Overview
A client supplies Job Template attributes to affect the rendering,
production and finishing of the documents in the job. Similar types of
instructions may also be contained in the document to be printed, that
is, within the Page Description Language (PDL) of the document data. If
there is a conflict between the value of one of these IPP Job Template
attributes, and a corresponding instruction in the document (either
implicit or explicit), it is desirable that the value of the attribute
shall take precedence over the document instruction. Until companies
that supply interpreters for PDLs, such as PostScript and PCL allow a
way to external attributes (such as IPP attributes) to take precedence
over internal job production instructions, a Printer might not be able
to implement the semantics that IPP attributes override (take on a
higher precedence) the embedded PDL instructions. Therefore, IPP
introduces a special Job Template attribute named "best-effort". This
attribute gives the end user some ability to influence, or at least
understand, how a particular Printer implementation handles these
conflicts.
This attribute takes on the following values:
- 'shall-honor-ipp-attributes': If a Printer supports this value and
a client requests this value, the Printer guarantees that all IPP
attribute values take precedence over embedded instructions in the
job data (the PDL of the job's documents).
- 'should-honor-ipp-attributes': If a Printer supports this value,
and a client requests this value, the Printer should try to make
sure that IPP attribute values take precedence over embedded PDL
instructions, however there is no guarantee
ISSUE: Should these be 'shall-honor-attribute-precedence' and 'should-
honor-attribute-prcedence'?
A Printer SHALL implement the "best-effort-supported" attribute. Notice
that since 'should-honor-ipp-attributes' does not offer any type of
guarantee, a Printer may not do a very "good" job of implementing the
semantics of "should", but it would still be a conforming
implementation.
If there is ever a conflict between what a Printer supports and what an
IPP client requests, the Printer shall reject the print request. A
client should query the printer to find out what is supported before
making a request. This ensures that all requested attribute values are
supported.
ISSUE: Should this be called "effort-level" rather than "best-effort"?
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4.6 Object Identity
All instances of Printer and Job objects have an identifier attribute
whose value is globally unique so that they can persistently and
unambiguously referenced. The IPP model requires that these values be
URIs as defined by RFC 1738 and RFC 1808. In addition to an identifier
attribute, instances of Printer and Job objects may have a name. An
object name need not be unique across all instances of all objects.
The Printer name is chosen and set by an administrator. The Job name is
created by the Printer using the name of the first document in the job.
In all cases, the name only has local meaning, and is not constrained to
be globally unique.
To summarize, each instance of Printer and Job objects will have two
identifying attributes:
- "xxx-URI": The globally unique identifier for this object instance
- "xxx-name": The non-globally unique name for this object instance
Document objects only have names, no identifiers. The "document-name"
attribute is used to store the name of the Document. This name is just
of interest within the context of a Job. It need not be globally
unique.
If Documents are printed by reference, they are identified by URIs.
5. IPP Operations
Jobs and Printers each have a set of associated operations. End users or
programs invoke these operations using an IPP client. The operations
are:
For a Printer object:
Create-Job (section 0)
Print-Job (section ???)
Get-Attributes (section 0)
Get-Jobs (section 0).
For a Job object:
Send-Document (section ??)
Cancel-Job (section 0)
Get-Attributes (section 0)
IPP Job and Printer objects are identified by URIs. When a client
communicates with a remote IPP object, it sends an operation request to
the URI for that object. Each request carries along with it the input
parameters and data required to perform the specified operation. Each
request requires a response from the object indicating success or
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failure of the operation including response data and/or error messages.
The representation and encoding of the IPP protocol are contained in
"Internet Printing Protocol: Protocol Specification."[23]
It is assumed that URIs for IPP Printers are available to end users or
programs that wish to invoke Printer operations. Although NOT
MANDATORY, it is RECOMMENDED that Printers be registered in a directory
service which end users and programs can interrogate. "Internet Printing
Protocol: Directory Schema"[24] defines the attributes to be associated
with a Printer entry in a directory service.
5.1 Operation Semantics
In this section, the IPP operations are described in terms of their
contents and semantics including both the request and the response.
In order to create a new Job object, a client MAY use one of two
operations: either the Create-Job operation or the Print-Job operation.
If the client wants to create a Job with only a single Document, the
client MAY use the Print-Job operation or a Create-Job operation
followed by a single Send-Document operation. For performance reasons,
the client SHOULD use the Print-Job operation for all single Document
Jobs. If the client wants to create a Job with more than one Document,
the client SHALL use the Create-Job operation followed by as many Send-
Document operations as needed (on Document per Send-Document operation).
The Print-Job operation is a convenience operation for creating a Job
with only one Document. Throughout this model specification, the term
create request is used to refer to either a Create-Job Request or a
Print-Job Request.
5.1.1 Print-Job Operation
When an end user desires to submit a print job with only one document,
the client sends a Print-Job Request to a Printer and receives a Print-
Job Response from that Printer. The information in a Print-Job Request
(along with any default information associated with the Printer) is
sufficient for the Printer to create a Job object and then process that
Job.
5.1.1.1 Print-Job Request
The following elements are part of the Print-Job Request:
Job Template Attributes:
An optional set of Job Template attributes as defined in section
6.2 Job Template Attributes. If the client supplies no Job
Template attributes in the Create-Job Request, the Printer uses its
default value attributes when processing the job.
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Document Content
The client either supplies the raw document data or a URI reference
to the data but not both.
The simplest Print-Job Request consists of just the Document Content and
nothing else. This means that the Printer SHALL create a new Job object
with no Job Template attributes and a single contained Document.
When a Printer receives a Print-Job Request, the Printer SHALL either
accept or reject the request. The Printer SHALL accept the Print-Job
Request and SHALL create a Job object if it is able to accept all
attributes in the request. The Printer SHALL reject the request and
SHALL NOT create a Job object if the Printer rejects any attribute in
the request. There are six cases to consider with respect to each Job
and Document attributes:
1. The client supplies a Job Template attribute named "xxx" and the
value supplied by the client is among the values supported by the
Printer (i.e., is among the values of the Printer's "xxx-supported"
attribute): The "xxx" Job Template attribute is accepted. If the
"best-effort-supported" attribute contains the value 'shall-honor-
ipp-attributes' the Printer SHALL guarantee the behavior
represented by the value in the "xxx" attribute (i.e., the IPP
attribute has precedence over any other embedded job instruction).
If the value of the "best-effort-supported" is 'should-honor-ipp-
attributes' then the Printer SHOULD try to realize the behavior
requested by the client, but NEED NOT guarantee the behavior. The
Printer creates the Job object and implements the "xxx" attribute
in the new Job object and uses the value supplied by the client.
2. The client supplies an attribute value but the attribute is
syntactically bad: The Printer shall reject the job and return the
??? error code.
3. The client supplies an attribute value and the attribute value is
not among the values supported by the Printer: The Printer SHALL
reject the job and return the 'attribute-unsupported' error code.
4. The client supplies an attribute value and the Printer does not
implement the attribute: The attribute is ignored. The Printer
behaves as if the attribute was never supplied by the client in the
Print-Job Request. In the response, the Printer SHALL return the
names of all ignored attributes. The final result of the Job is
undefined for an ignored attribute (that is the desired behavior
might or might not be realized).
ISSUE: Should the printer just reject the job?
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5. The client does not supply an attribute, but the Printer
implements the attribute: The attribute is accepted and when the
Printer creates the Job object, the Printer SHALL NOT implement the
attribute in the Job object. When the Printer processes that Job,
the Printer SHOULD attempt to use the behavior implied by the
default value Printer attribute as set at the time of Job
processing (not Job creation). In other words, these rules allow
for a Job object to be created without implementing some of the Job
Template attributes. As the Printer processes the Job, if the
Printer implements a default value attribute for the missing Job
Template attribute, the Printer does its best to realize the
behavior of the default value. If the Printer does not implement
the default value attribute, the results are undefined.
Note: For each Job Template attribute, this specification REQUIRES
that a Printer to implement the CONDITIONALLY MANDATORY attributes.
6. The client does not supply an attribute, and the Printer does not
implement the attribute: The Printer accepts the Job and creates a
Job object. When the Job is processed, the actual behavior
realized with respect to the missing Job Template attribute is
undefined.
5.1.1.2 Print-Job Response
The Printer shall return to the client the following output parameters
as part of the Print-Job Response:
Job Identifier:
A URI which the client shall use for all other operations on this
Job
Job Status:
The following Job attributes: job-name, job-state, and job-state-
reasons. The value of each attribute shall be from a snapshot
taken sometime after the time the Printer receives the print
request. The "job-state-message" attribute is OPTIONAL.
Note: Since any job affecting printer state information is
reflected in the "job-state" and "job-state-reasons" job
attributes, it is sufficient to return only job status attributes
and no printer status attributes at Job creation time.
Ignored Attributes:
A list of attribute names which were ignored in the creation of the
Job object.
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Unsupported Attributes:
A list of attribute names which are unsupported. Any attributes in
this list imply that the Job object was not created.
Bad Attributes:
A list of attribute names which were syntactically incorrect. Any
attributes in this list imply that the Job object was not created.
Status
Status information including error status
The simplest response shall consist of the job identifier, the Job
Status attributes, and an operation status that is either an "ok" status
or an "error" status.
5.1.2 Create-Job Operation
When an end user desires to submit a print job, the client sends a
Create-Job Request to a Printer and receives a Create-Job Response from
that Printer. The information in a Create-Job Request along with any
default information associated with the Printer is sufficient for the
Printer to create a Job object. An instance of a Job object contains
all the information needed by the Printer to print one or more documents
as a print job. If the client follows the Create-Job operations with as
many Send-Document operations as needed.
5.1.2.1 Create-Job Request
The following elements are part of the Create-Job Request:
Number of Documents:
An optional integer value specifying the number of Documents for
this Job. The document data is transferred in a series of
subsequent Send-Document operations (one document per Send-Document
operation). If this value is not supplied by the client, the
Printer waits to receive an empty Send-Document operation signaling
the end of Documents for this Job. If the client wants to create a
Job with only a single document, the client MAY use the Print-Job
operation. This is a convenience operation for creating a Job with
only one Document. The Print-Job Operation is semantically the
same as a Create-Job operation followed by one Send-Document
operation.
Job Template Attributes:
An optional set of Job Template attributes as defined in section
6.2 Job Template Attributes. If the client supplies no Job
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Template attributes in the Create-Job Request, the implemented
Printer defaults are used.
The simplest Create-Job Request has no data which means that the Printer
SHALL create a new Job object with no Job Template attributes and the
number of Documents is yet to be determined.
When a Printer receives a Create-Job Request, the Printer SHALL
either accept or reject the request. The rules for accepting or
rejecting a Create-Job Request are the same as the rules for
accepting or rejecting the Print-Job Request (see section 5.1.1.1
Print-Job Request).
5.1.2.2 Create Job Response
The Printer shall return to the client the following output parameters
as part of the Create-Job Response:
Job Identifier:
A URI which the client shall use for all other operations on this
Job
Job Status:
The following Job attributes: job-name, job-state, and job-state-
reasons. The value of each attribute shall be from a snapshot
taken sometime after the time the Printer receives the print
request.
Note: Since any job affecting printer state information is
reflected in the "job-state" and "job-state-reasons" job
attributes, it is sufficient to return only job status attributes
and no printer status attributes at Job creation time.
Ignored Attributes:
A list of attribute names which were ignored in the creation of the
Job object.
Unsupported Attributes:
A list of attribute names which are unsupported. Any attributes in
this list imply that the Job object was not created.
Bad Attributes:
A list of attribute names which were syntactically incorrect. Any
attributes in this list imply that the Job object was not created.
Status
Status information including error status
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The simplest response shall consist of the job identifier, the Job
Status attributes, and an operation status that is either an "ok" status
or an "error" status.
5.1.3 Send-Document Operation
Once a Job object has been created using a Create-Job operation, a
client uses the Send-Document operation to transport the documents to be
printed and add them to the named Job object. A document MUST be sent
in a single Send-Document operation.
5.1.3.1 Send-Document Request
The client submits the request to a Job URI.
The following abstract data types are part of the Send-Document Request:
Document Attributes:
An optional set of Document Description attributes (section 6.4
Document Attributes).
Document Content:
The client either supplies the raw document data or a URI reference
to the data but not both.
5.1.3.2 Send-Document Response
The following abstract data types are part of the Send-Document
Response:
Job Status:
The following Job attributes: job-name, job-state, and job-state-
reasons. The value of each attribute shall be from a snapshot
taken sometime after the time the Printer receives the print
request.
Note: Since any job affecting printer state information is
reflected in the "job-state" and "job-state-reasons" job
attributes, it is sufficient to return only job status attributes
and no printer status attributes at Job creation time.
Ignored Attributes:
A list of attribute names which were ignored in the creation of the
Job object.
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Unsupported Attributes:
A list of attribute names which are unsupported. Any attributes in
this list imply that the Job object was not created.
Bad Attributes:
A list of attribute names which were syntactically incorrect. Any
attributes in this list imply that the Job object was not created.
Status:
Status information including error status
5.1.4 Cancel Job Operation
This operation allows a user to cancel one specific Print Job any time
after the print job has been established on the Printer. Some pages may
be printed before a job is terminated if printing has already started
when the Cancel Job operation is received. Only the end user who is
also the job originator ("job-originating-user" Job attribute) can
cancel the job using IPP 1.0.
5.1.4.1 Cancel-Job Request
The client submits the request to a Job URI.
The following abstract data types are part of the Cancel Job Request:
Message:
Optional message to the operator
5.1.4.2 Cancel-Job Response
The following information is part of the Cancel Job Response:
Status:
Status information including error status
5.1.5 Get-Attributes Operation
The Get-Attributes operation allows client to obtain information from a
Printer or Job object. The client supplies the set of attributes names
and/or attribute group names that the requester is interested in as
operation input parameters. The Printer shall return a corresponding
attribute list in the response with the appropriate attribute values
filled in for each attribute (explicitly named or implicitly included in
an attribute group) that the client supplied in the request.
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5.1.5.1 Get-Attributes Request
The client shall submit the Get-Attributes request to a Job URI or
Printer URI.
The following input parameters shall be part of the Get-Attributes
Request:
Document Format:
The client shall supply this input parameter only when requesting
attributes of the Printer object. The Printer shall reject this
request, if this input parameter is supplied for a Job object.
This input parameter conditions the Printer attributes and values
that might depend on the document format. The Printer shall return
only (1) those attributes that are implemented and (2) the
attribute values that are supported for the specified document
format. By specifying the document format, the client can
eliminate the attributes that are not implemented and values that
are not supported for the document format that the client has or is
able to generate.
If the client omits this input parameter, the effect shall be the
same as if the value of the Printer's document format attribute
were supplied. It is recommended that the client always supply a
value for document-format, since the Printer's default value for
document-format may be 'auto-sense', in which case the returned
attributes and values are for the union of the document formats
that the Printer supports in its 'auto-sense' support."
Requested Attributes:
An optional set of attribute names (without values) or attribute
group names in whose values the requester is interested. If the
client omits this input parameter, the effect shall be the same as
if the "all" attribute group were supplied.
Attributes may be requested by name or by group name. For Jobs, the
attribute groups include:
- 'job-template': the attributes specified in Section 6.3.1 Job
Template Attributes.
- 'job-description': the attributes specified in Section 6.3.2 Job
Description Attributes.
For Printers, the attribute groups include:
- 'printer-job-template': the attributes specified in Section 6.5.1
Printer Job Template Attributes.
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- 'printer-description': the attributes specified in Section 6.5.2
Printer Description Attributes.
There are also special groups:
- 'none': no attributes of the specified object. Note: none is
primarily useful in Get-Jobs, but can be used as a "ping" with the
Get-Attributes operation.
- 'all': all attributes of the specified object
5.1.5.2 Get-Attributes Response
The Printer shall return the following output parameters as part of the
Get-Attributes Response:
Result Attributes:
The requested attributes of the object with their current values,
if the requester supplied any Requested Attributes. If the request
did not supply any attribute names, the Printer shall assume that
the client is implicitly requesting the default group of "all" and
shall return all attributes implemented for the specified Job or
Printer object.
Unimplemented Attributes:
A list of attribute names which are unimplemented.
Unknown:
A list of attribute names which are unknown.
Status:
Status information including error status
A Printer may choose, for security reasons, not to return all attributes
that a client requests. It may even return none of the requested
attributes. In such cases, the status returned is the same as if the
Printer had returned all requested attributes. The client cannot tell by
such a response whether the requested attribute was present or absent on
the Printer.
In response to a "Get-Attributes" (or a "Get-Jobs") operation the
following requirements apply to the Printer:
1. If the client supplies an attribute name in the Requested
Attribute input parameter and that attribute is implemented by the
Printer, the printer shall respond with all current values for that
attribute. If the value of an implemented attribute is unknown for
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some reason, the Printer shall respond with the attribute name in
the "unknown attribute list" response parameter.
2. If the client supplies an attribute name in the Requested
Attribute input parameter that attributed is not implemented by the
Printer, the Printer shall respond with the attribute name in the
"unimplemented attribute list" response parameter.
3. If the client supplies an attribute group that is implemented by
the Printer, the Printer shall respond with all current values for
each implemented attribute in the group. It shall not respond for
unimplemented attributes in the group. If the value of an attribute
is unknown for some reason, the Printer shall respond with the
attribute name in the "unknown attribute list" response parameter.
4. If the client supplies an attribute group keyword that is not
implemented, the Printer has no means for determining if it is an
unimplemented attribute or attribute group. In this case, the
Printer assumes that it is an unimplemented attribute and responds
as if it is an unimplemented attribute (the Printer responds with
the attribute name in the "unknown attribute list" response
parameter).
5.1.6 Get-Jobs Operation
The Get-Jobs operation allows a client to retrieve Printer attributes
and a list of print jobs belonging to the target Printer object. A list
of Job attribute names or attribute group names that the client is
interested in seeing may be included in the request.
This operation is like Get-Attributes, except that Get-Jobs operation
returns attributes from more than one object.
5.1.6.1 Get-Jobs Request
The client shall submit the Get-Jobs request to a Printer URI.
The following input parameters are part of the Get-Jobs Request:
Job Owner
This is the user-name. If the value is non-null, then the
requester wants only those jobs whose job-originating-owner is the
same as the specified user-name. If the value is null, then the
requester wants all jobs.
Limit
This is an integer value which indicates a limit to the number of
Jobs returned. The limit is a "stateless limit" in that if the
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limit is n then only the first n jobs are returned in the Get-Jobs
Response; there is no mechanism to allow for the "next" n jobs.
The limit applies across all Job States requested. For example, if
the limit if 50, and there are 75 jobs in the 'completed' state and
25 in the 'pending state' and the client requests first 'completed
jobs' and then 'pending' jobs, only the first 50 'completed' jobs
are returned. The other 25 'completed' jobs are not returned and
neither are any of the 'pending' jobs returned.
Job States
A possibly empty set of job state values. If the set is not empty,
then the requester wants only those jobs whose job-state is the
same as one of the specified job state values. If this operation
parameter has more than one value, the Printer SHALL return the
jobs grouped by state with each group being in the same order as
supplied by the client in this parameter. Within each group, the
jobs are ordered from oldest to newest with respect to completion
time (either actual or expected). For example, if the client
requests all 'pending' and 'completed' jobs, first all jobs in the
'pending' state are returned (ordered from oldest to newest) and
then all jobs in the 'completed' state are returned (ordered from
oldest to newest). If the client request all 'completed' and
'processing' jobs, first all jobs in the 'completed' state are
returned (ordered from oldest to newest) and then all jobs in the
'processing' state are returned (oldest to newest). If the client
does not supply this operation parameter, the value SHALL be
assumed to be (by both the client and the Printer) first 'pending'
and then 'processing'.
Requested Job Attributes:
A optional set of attribute names (without values) or attribute
groups names in whose values the requester is interested from each
of the jobs on the specified Printer. The attribute group names
are the same as for the Get-Attributes operation for the Job
object. If the client omits this input parameter, the effect shall
be the same as if the 'none' attribute group were supplied.
5.1.6.2 Get-Jobs Response
The Printer shall return the following output parameters as part of the
Get-Jobs Response:
Result Attributes:
The result includes zero or more objects each with zero or more
attributes. Each Job is returned in chronological order. This
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order is explicitly defined to be: oldest to newest with respect to
completion time, either actual or expected.
If the client did not supply any Job attributes, the Printer shall
assume that the client is implicitly requesting the 'none' group
(that is no Job attributes are returned, just the Job URI for each
Job).
Status
Status information including error status
A Printer may choose, for security reasons, not to return all attributes
that a client requests. It may even return none of the requested
attributes. In such cases, the status returned is the same as if the
Printer had returned all requested attributes. The client cannot tell by
such a response whether the requested attribute was present or absent on
the Printer.
5.2 Operation Status and Messages
The Status code provides information on the results of a request.
The Message provides a short textual description of the Status. The
Status is intended for use by automata and the Message is intended
for the human user. An IPP application (i.e. a browser, GUI, print
driver or gateway) is not required to examine or display the Message.
5.3 Status Codes (type2 keyword)
Each Status is described below, including a description of which
operation(s) it can follow and any meta-information required in the
response.
ISSUE: Keith's doc still need to go here.
6. Object Attributes
This section describes the attributes with their corresponding syntaxes
and values that are part of the IPP model. The sections below show the
objects and their associated attributes which are included within the
scope of this protocol. Many of these attributes are derived from other
relevant specifications:
- ISO/IEC 10175 DPA (Final, June 1996)
- RFC 1759 Printer MIB (Proposed Standard, May 1995)
- Internet-Draft: Printer MIB (Draft Standard in progress, December
1996)
- Internet-Draft: Job Monitoring MIB (I-D in progress, March 1997)
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Each attribute is uniquely identified in this document using a "keyword"
in the section header describing that attribute. A keyword is a
sequence of characters (length of 1 to 255) which consists of just
letters, digits, hyphen ("-"), and underscore ("_"). With these
restrictions, there will be a straight forward encoding of these
keywords onto real values in the protocol specification. Not only are
attributes uniquely identified with keywords, some attributes take on a
syntax which is a set of keywords. This set of keywords represents the
domain of the attribute.
6.1 Attribute Syntaxes
The following table shows the basic syntax types that a client and
server shall be able to handle.
Table 1 - Attribute Syntaxes
Basic Type Description Comments
text a sequence of For free form human
characters; readable text
length: 0 to intended for human
4095; consumption.
characters: any
name a sequence of For referencing some
characters; object via a user-
length: 1 to friendly string,
255; such as a Printer
characters: any name, a document
name, a user name,
or a host name. May
include the SPACE
character.
Note: The protocol
may need to provide
means to quote the
SPACE character if
the protocol uses
SPACE for other
purposes.
fileName a sequence of For referencing some
characters; file. The limit is
length: 1 to the same as POSIX
1024;
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Basic Type Description Comments
characters: any and NT.
keyword a sequence of
characters; identifiers of
length: 1 to entities in the
255; abstract protocol
characters: (specified in this
letters, digits, document). These
hyphen ("-"), entities can be
For semantic
underscore ("_") attribute names or
values of
attributes, When a
keyword is used to
represent an
attribute (its
name), it must be
unique within the
full scope of IPP
objects and
attributes. When a
keyword is used to
represent a value of
an attribute, it
must be unique just
within the scope of
that attribute.
That is, a keyword
can not be used for
two different values
of the same
attribute to mean
two different
semantic ideas.
However, the same
keyword can be used
across two or more
attributes,
representing
different semantic
ideas for each
attribute.
uri a sequence of Universal Resource
characters as Identifier
defined in
rfc1738 and
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Basic Type Description Comments
rfc1808
uriScheme a sequence of "http" for HTTP
characters schemed URIs (e.g.,
representing the http://...). "ftp"
URI Scheme for FTP schemed URIs
(e.g., ftp://...).
locale a standard ISSUE: What standard
identifier for values will be used
language and for locale?
character set
octetString a sequence of Used for opaque
octets data, such as the
document-content.
boolean two values of like an keywordSet,
'true' and but there are only
'false' two values. Note: An
application might
use a checkbox for
such a value.
integer an integer value each attribute
that is in the specifies the range
range from - constraint
2**31 to 2**31 - explicitly.
1
dateTime a value that absolute date and
holds the date time
and time to the
nearest second.
seconds a non-negative a relative time
integer with
implicit units
of seconds
milliseconds a non-negative a relative time
interger with
implicit units
of milliseconds
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Basic Type Description Comments
integerUnits an integer with an integer value
explicit units expressed in units
ISSUE: we have two
types with implicit
units and one with
explicit units where
the units are
specific for one
attribute:
"printer-speed".
1setOf X 1 or more values for sets of values
of type X.
rangeOf X a range of value for a range of
of type X values, such as
integers
6.1.1 Attribute Extensibility
This document uses prefixes to the keyword basic syntax type in order
to communicate extra information to the reader through its name. This
extra information need not be represented in an implementation
because it is unimportant to a client or Printer. The table below
describes the prefixes and their meaning.
ISSUE: There are some references to the Printer Working Group (PWG).
How do we describe in this document the process for the PWG to
approve type 2 extensions?
Basic Prefix Comments
Type
keyword type1 someone must revise the IPP standard
to add a new name. No private names
are allowed.
keyword type2 implementers can, at any time, add new
values by proposing them to the PWG
for registration (or an IANA-appointed
registry advisor after the PWG is no
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Basic Prefix Comments
Type
longer certified) where they are
reviewed for approval. IANA keeps the
registry. Implementers can support
private (unregistered) with a suitable
distinguishing prefix, such as -xxx-
where xxx is the company name
registered with IANA for use in domain
names.
keyword type3 implementers can, at any time, add new
values by submitting a registration
request directly to IANA, no PWG or
IANA-appointed registry advisor review
is required. Implementers can support
private (unregistered) names with a
suitable distinguishing prefix, such
as -xxx- where xxx is the company name
registered with IANA for use in domain
names.
keyword type4 system administrators can, at any
time, add new installation-defined
names to a local system. Care should
be taken by the administrator to see
that keywords do not conflict with
other keywords defined by the standard
or as defined by the implementing
product. There is no registration or
approval procedure for type 4
keywords.
ISSUE: Since the standard specifies
some of the type 4 values, shouldn't
it be possible to register additional
type 4 values after the standard is
approved?
Note: This standard defines keyword values for all of the above types.
6.2 Job Template Attributes
Job Template attributes describe job processing behavior. Take for
example, a generic Job Template attribute called "xxx":
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1. "xxx" is optionally supplied by the client in a create request.
If "xxx" is supplied, the client is specifying that the Printer
will apply a specific job processing behavior to this job while
processing the Job. When "xxx" is not supplied, the client expects
the Printer will apply the default job processing behavior.
2. "xxx-supported" is a Printer attribute that describes what is
behaviors are supported by that Printer. "xxx-supported" is a
CONDITIONALLY MANDATORY attribute which means that the Printer
only implements the attribute if it is capable of realizing one or
more of the behaviors associated with the attribute and its values.
A client can query the Printer and find out what behaviors are
supported by inspecting at the values in the "xxx-supported"
attribute.
3. The Printer also implements a default value attribute named "xxx".
This default value attribute describes what will be done when no
other job processing information is supplied by the client (either
explicitly as an IPP attribute in the create request or implicitly
as an embedded instruction within the job data). Along with the
supported attribute, the default value attribute is also
CONDITIONALLY MANDATORY. However, if the Printer implements the
"xxx-supported" attribute, the Printer MUST implement the
corresponding default value attribute and vice versa.
4. The Printer OPTIONALLY implements the "xxx-available" attribute.
This attribute describes a state of readiness for each supported
attribute. The supported and available attributes have the same
number of attributes and are ordered so that there is a set of
ordered value pairs between the two attributes. The availability
state of a supported attribute value indicates the level of effort
required by the Printer to actually use resource indicated by the
supported value. The following values are used in the "xxx-
available" attributes:
'ready' - the resource can be used by a Job without human
intervention (the resource is not exhausted)
'not-ready' - the use of the resource requires human intervention
(the resource may be exhausted or not automatically available)
Note: The "xxx-available" attribute only applies to the "media" and
"finishings" attributes.
5. If a client application wishes to present an end user with a list
of supported and default values from which to choose, the client
program should query the supported, default values, and possibly
the available attributes. The values that the client then sends in
the create request will all fall within the supported values at the
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Printer. When querying the Printer, the client MAY enumerate each
attribute by name in the Get-Attributes Request, or the client MAY
just name the "printer-job-template" group in order to get the
complete set of supported, default value, and available attributes
which are implemented.
The "job-priority" attribute is an example of a Job Template attribute.
It is an integer in the range from 1 to 100. A client can query the
Printer for the "job-priority-supported" attribute and the "job-
priority" default value attribute. The supported attribute contains a
set of supported priority values (a range). The default value attribute
contains job priority value that will be used for a new job if the
client does not supply one in the create request. If the client does
supply the "job-priority" attribute, the Printer validates the value to
make sure that it falls within the range of supported values. If the
client-supplied value is supported, the Job object is created and the
"job-priority" attribute is populated with that value. The Job object,
when queried, returns the value supplied by the client. If the client
does not supply a "job-priority" value in the create request, the Job
object is created, but no "job-priority" attribute is implemented for
the Job. The client queries the Printer's default value "job-priority"
value to find out at what priority the job will be processed.
The following table summarize the names, relationships, and conformance
requirements for all Job Template attributes. The following general
rules apply to implementation requirements:
1. In a create request, all Job Template attributes are OPTIONAL.
2. In a Printer Object, all supported attributes are CONDITIONALLY
MANDATORY.
3. All Printer default value attributes are CONDITIONALLY MANDATORY.
However, if the supported attribute is implemented then the default
value attribute MUST be implemented and vice versa.
4. All "available" attributes are OPTIONAL.
The table only shows exceptions to the above rules. The first column
of the table (Job) shows the name and syntax for each Job Template
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attribute in the Job object (in the create request, the same name and
syntax is used). The next three columns show the name and syntax for
each Job Template attribute in the Printer object (the default value
attribute, the supported attribute, and the available attribute). A
"No" in the table means the Printer SHALL NOT implement the attribute.
Job Printer Printer Printer
Default Value Supported Available
job-name No No No
(name, MAN))
job-sheets job-sheets job-sheets- No
(type4 keyword) (type4 keyword) supported
(1setOf type4
keyword)
notificaiton- notification- No
events events events
(1setOf type2 (1setOf type2
notification-
(1setOf type2
keyword) keyword) keyword)
notification- No notification- No
addresses addresses-
(1setOf uri) supported
(1setOf uri
scheme)
job-priority job-priority job-priority- No
(int) (int) supported
(rangeOf int)
job-hold-until job-hold-until job-hold-until- No
(type4 keyword) (type4 keyword) supported
(1setOf type4
keyword)
multiple- multiple- multiple- No
documents-are documents-are documents-are-
(type2 keyword) (type2 keyword) supported
(1setOf type2
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Job Printer Printer Printer
Default Value Supported Available
keyword)
best-effort best-effort best-effort- No
(type2 keyword) (type2 keyword, supported
MAN) (1setOf type2
keyword, MAN)
media media media-supported media-available
(type4 keyword) (type4 keyword) (1setOf type2 (1setOf avail
keyword) keyword)
number-up number-up number-up-
(type3 keyword) (type3 keyword) supported
(1setOf type3
keyword)
sides sides sides-supported
(type2 keyword) (type2 keyword) (1setOf type2
keyword)
printer- printer- printer-
resolution resolution resolution-
(type2 keyword) (type2 keyword) supported
(1setOf type2
keyword)
print-quality print-quality print-quality -
(type2 keyword) (type2 keyword) supported
(1setOf type2
keyword)
finishings finishings finishings- finishings-
(setOf type2 (setOf type2 supported available
keyword) keyword) (setOf type2 (setOf avail
keyword) keyword)
copies copies copies-supported No
(int) (int) (rangeOf int)
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Job Printer Printer Printer
Default Value Supported Available
compression compression compression- No
(type3 keyword) (type3 keyword) supported
(1setOf type3
keyword)
job-k-octets No job-k-octets-
supported
No
(int)
(rangeOf int)
job-impressions No job-impressions- No
(int) supported
(rangeOf int)
job-media-sheets No job-media- No
(int) sheets-supported
(rangeOf int)
6.2.1 job-name (name)
This attribute defines the name of the job. It is a name that is more
user friendly than the job-URI.
If "job-name" is not supplied in the in the create request, the Printer,
on creation of the Job, shall generate a name which is the name of the
first document in the job. This name comes from the "document-name"
attribute or "document-URI" attribute depending on which attribute is
supplied in the Create-Job Request for the first document. If "job-
name" is supplied in the Create-Job Request, the Printer uses its value
as the name of the created Job.
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6.2.2 job-sheets (type4 keyword)
This attribute determines which of any banner page(s) shall be printed
with a job.
Standard values are:
'none': no job sheet is printed
'standard': a site specific standard job sheet is printed
extensions: names the specific job sheet (banner page)
To force no job sheets, the system administrator SHALL set the only
supported value to 'none'.. To force the use of banner pages, the
supported values shall not include 'none'. If a client requests 'none'
in the create request, the request is rejected.
6.2.3 notification-events (1setOf type2 keyword)
This attribute specifies the events for which the end user desires some
sort of notification. The "notification-addresses" attribute is used to
describe the destination addresses for these events.
Standard values are:
'none': the Printer shall not notify
'all': the Printer shall notify when any of event occurs.
'job-completion': the Printer shall notify when the job containing
this attribute completes with or without errors.
'job-canceled': the Printer shall notify when the job containing
this attribute is canceled by the end-user or by the operator, or
aborts before completion.
'job-problems': the Printer shall notify when this job has a problem
while this job is printing. Problems include any of the "job-state-
reasons" or "printer-state-reason" values
'printer-problems': the Printer shall notify when any job, including
this job, is affected by a Printer problem (the printer has moved
to the stopped state and there is a reason in the printer-state-
reasons attribute) while this job is waiting to print or printing.
Problems include any of the "job-state-reasons" or "printer-state-
reason" values
6.2.4 notification-addresses (1setOf uri)
This attribute describes both where (the address) and how (the mechanism
for delivery ) notification events are to be delivered. The Printer
shall use this attribute as the set of addresses and methods for sending
messages when an event occurs that the end user (job submitter) has
registered an interest in.
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Standard uri scheme values are:
'mailto': email is used
'http': an HTTP method is used to add HTML formatted events to the
end of the specified HTML file.
'ftp': FTP is used to append a record at the end of a specified text
file.
6.2.5 job-priority (integer(1:100))
This attribute specifies a priority for scheduling the print-job. A
higher value specifies a higher priority. The value 1 is defined to
indicate the lowest possible priority. The value 100 is defined to
indicate the highest possible priority. Priority is expected to be
evenly or "normally" distributed across this range. Among those jobs
that are ready to print, a Printer shall print all jobs with a priority
value of n before printing those with a priority value of n-1 for all n.
The mapping of vendor-defined priority over this range is
implementation-specific.
6.2.6 job-hold-until (type4 keyword)
This job attribute specifies the named time period during which the Job
print job shall become a candidate for printing.
Standard values for named time periods are:
'no-hold': immediately, if there are not other reasons to hold the
job.
'day-time': during the day.
'evening': evening
'night': night
'weekend': weekend (Saturday or Sunday)
'second-shift': second-shift
'third-shift': third-shift (after midnight)
An administrator shall associate allowable print times with a named time
period (by means outside IPP 1.0). An administrator is encouraged to
pick names that suggest the type of time period.
If the value of this attribute specifies a time period that is in the
future, the Printer shall add the 'job-hold-until-specified' value to
the job's "job-state-reasons" attribute and shall not schedule the
print-job for printing until the specified time-period arrives. When
the specified time period arrives, the Printer shall remove the 'job-
hold-until-specified' value from the job's "job-state-reason attribute"
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and, if no other reasons remain, shall consider the job as a candidate
for processing.
If this job attribute value is the named value "'no-hold'", or the time
period has already started , the job shall be a candidate for processing
immediately.
6.2.7 multiple-documents-are (type2 keyword)
This job attribute is relevant only if a job consists of two or more
documents. It controls finishing operations, job-sheet placement, and
the order of documents when the copies attribute exceeds 1.
Standard values are:
'single-document': If the files for the job are a and b, then files a
and b are treated as a single document for finishing operations.
Also, there will be no slip sheets between files a and b. If more
than one copy is made, the ordering shall be a, b, a, b, ....
'separate-documents-uncollated-copies': If the files for the job are
a and b, then each file is treated as a single document for
finishing operations. Also, a client may specify that a slip sheet
be placed between files a and b. If more than one copy is made,
the ordering shall be a, a, b, b, ....
'separate-documents-collated-copies': If the files for the job are a
and b, then each file is treated as a single document for finishing
operations. Also, a client may specify that a slip sheet be placed
between files a and b. If more than one copy is made, the ordering
shall be a, b, a, b, ....
Both of the 'separate-xxx' values force each new document to start on a
new media sheet.
6.2.8 best-effort (type2 keyword)
This attribute determines what to do if there is a conflict between what
a client requests and what a Printer supports.
Standard values for this attribute are:
- 'shall-honor-ipp-attributes': If a Printer supports this value and
a client requests this value, the Printer guarantees that all IPP
attribute values take precedence over embedded instructions in the
job data (the PDL of the job's documents).
- 'should-honor-ipp-attributes': If a Printer supports this value,
and a client requests this value, the Printer should try to make
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sure that IPP attribute values take precedence over embedded PDL
instructions, however there is no guarantee
The client supplies Job Template attributes in the create request to
affect the rendering, production and finishing of the documents in the
job. Similar types of instructions may also be contained in the
document to be printed, that is, within the Page Description Language
(PDL) of the document data. If there is a conflict between the value of
one of these attributes, and a corresponding instruction in the document
(either implicit or explicit), it is desireable that the value of the
attribute shall take precedence over the document instruction. Many of
these job template attributes provides a client with a way to request
some feature at print time that might not have been embedded within the
document data when the document was created. Job template attribute
also provides a client with a way to override a feature at print time
that was embedded within the document data when the document was
created. Note: until companies that supply interpreters for PDLs, such
as PostScript and PCL allow a way to specify overrides for internal job
production instructions, a Printer might not be able to implement these
attributes for some PDLs.
In order to solve this problem, the IPP Printer implements the MANDATORY
best-effort-supported" attribute. If the value of this attribute is
'shall-honor-ipp-attributes', the implementation MUST guarantee that the
IPP attribute values take precedence over any related job processing
instructions in the PDL Job's document data. This can be done by
modifying the interpreter within the output device itself to understand
IPP attributes, or by mergeing theses Job Template attributes directly
into the document data, or in any other implementation specific manner.
In any case, the semantics of 'shall-honor-ipp-attributes' MUST be
preserved.
Note: Since 'should-honor-ipp-attributes' does not offer any type of
guarantee, a Printer may not do a very "good" job of implementing the
semantics of "should", but it would still be a conforming
implementation.
This "best-effort" attribute has nothing to do with conflict between
what a Printer supports and what an IPP client requests. If there is
such a conflict, the Printer shall reject the create request. A client
SHOULD query the printer to find out what is supported before supplying
specific values in a create request.
6.2.9 media (type4 keyword)
This job attribute identifies the medium that the Printer shall use for
all pages of the document regardless of what media are specified within
the document.
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The values for medium include medium-names, medium-sizes, input-trays
and electronic forms so that one attribute specifies the media. If a
printer allows a client to specify a medium name as the value of this
attribute, such a medium name implicitly selects an input-tray that
contains the specified medium. If a printer allows a client to specify
a medium size as the value of this attribute, such a medium size
implicitly selects a medium name which in turn implicitly selects an
input-tray that contains the medium with the specified size. If a
printer allows a client to specify an input-tray as the value of this
attribute, such an input-tray implicitly selects the medium that is in
that input-tray at the time the job prints. This case includes manual-
freed input-trays. If a printer allows a client to specify an
electronic form as the value of this attribute, such an electronic form
implicitly selects a medium-name which in turn implicitly selects an
input-tray that contains the medium specified by the electronic form.
The electronic form also implicitly selects an image that the Printer
shall merge with the data from the document as its prints each page.
Standard values are (taken from ISO DPA and the Printer MIB):
default:
iso-a4-white:
...
6.2.10 number-up (type3 keyword)
This job attribute specifies the number of source page-images to impose
upon a single side of an instance of a selected medium.
Standard values are:
'none': The Printer shall not include any embellishments and shall
place one logical page on a single side of an instance of the
selected medium without any translation, scaling, or rotation.
'one': The Printer shall place one logical page on a single side of
an instance of the selected medium but is allowed to add
embellishments or some sort of translation, scaling, or rotation.
'two':
'four':
This attribute primarily controls the translation, scaling and rotation
of page images, but a site may choose to add embellishments, such as
borders to each logical page.
6.2.11 sides (type2 keyword)
This attribute specifies how source page-images are to be imposed upon
the sides of an instance of a selected medium.
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The standard values are:
'one-sided': imposes each consecutive source page-image upon the same
side of consecutive media sheets.
'two-sided-long-edge': imposes each consecutive pair of source page-
image upon front and back sides of consecutive media sheets, such
that the orientation of each pair of source-pages on the medium
would be correct for the reader as if for binding on the long edge.
This imposition is sometimes called "duplex".
'two-sided-short-edge': imposes each consecutive pair of source page-
image upon front and back sides of consecutive media sheets, such
that the orientation of each pair of source-pages on the medium
would be correct for the reader as if for binding on the short
edge. This imposition is sometimes called "tumble" or "head-to-
toe".
'two-sided-long-edge' and 'two-sided-short-edge' work the same for
portrait or landscape. That is, "head-to-toe" is "tumble" in portrait
but "duplex" in landscape. "head-to-head" also switches between
"duplex" and "tumble" when using portrait and landscape modes.
6.2.12 printer-resolution (type2 keyword)
This job attribute specifies the resolution that the Printer should use.
The values are type2 keywords which represent single integers or pair of
integers. The latter are to specify the resolution when the x and y
dimensions differ. When two integers are specified, the first is in the
x direction, i.e., in the direction of the shortest dimension of the
medium, so that the value is independent of whether the printer feeds
long edge or short edge first.
The standard values are:
normal:
res-100:
res-300x300:
...
6.2.13 print-quality (type2 keyword)
This job attribute specifies the print quality that the Printer should
use.
The standard values are:
draft: lowest quality available on the printer
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normal: normal or intermediate quality on the printer
high: highest quality available on the printer
6.2.14 copies (integer(1:2**31 - 1))
This job attribute specifies the number of copies of the job to be
printed. Note: The effect of this attribute on jobs and documents is
controlled by the multiple-files-are job attribute.
6.2.15 finishings (1setOf type2 keyword)
This job attribute identifies the finishing operation that the Printer
should apply to each copy of each printed document in the job where the
definition of a copy is controlled by the "multiple-documents-are" Job
attributes.
Standard values are:
none:
staple:
...
6.2.16 compression (type3 keyword)
This attribute identifies compression algorithms used for compressed
document data.
Standard values for this attribute are:
'none':
'zip':
'tar':
...
6.2.17 job-k-octets (integer(0:2**31 - 1))
This Job attribute specifies the total size of the job in K octets,
i.e., in units of 1024 octets. The value shall be rounded up, so that a
job between 1 and 1024 octets shall be indicated as being 1K, 1025 to
2048 shall be 2, etc. This attribute is not intended to be a counter as
in the Job Monitoring MIB; it is intended to be useful routing and
scheduling information if known. The Printer might not be able to
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compute this value (if not supplied by the client in the request) at the
time the Job is created. If not, the Printer may implement this
attribute at any later time as it is able to compute the total size of
the Job.
6.2.18 job-impressions (integer(0:2**31 - 1))
This job attribute specifies the total size of the job in impressions.
This attribute is not intended to be a counter as in the Job Monitoring
MIB; it is intended to be useful routing and scheduling information if
known. The Printer shall try to compute the value if it is not supplied
in the create request. The Printer might not be able to compute this
value (if not supplied by the client in the request) at the time the Job
is created. If not, the Printer may implement this attribute at any
later time as it is able to compute the total size of the Job.
6.2.19 job- media-sheets (integer(0:2**31 - 1))
This job attribute specifies the total size of the job in media-sheets.
This attribute is not intended to be a counter as in the Job Monitoring
MIB; it is intended to be useful routing and scheduling information if
known. The Printer shall try to compute the value if it is not supplied
in the Create-Job Request. The Printer might not be able to compute
this value (if not supplied by the client in the request) at the time
the Job is created. If not, the Printer may implement this attribute at
any later time as it is able to compute the total size of the Job.
6.3 Job Attributes
The attributes in this section are associated with a Job.
6.3.1 Job Template Attributes
The Job Template attributes which apply specifically to a Job object are
described in section 6.2 Job Template Attributes. These Job specific
attributes form the attribute group called "job-template".
6.3.2 Job Description Attributes
These attributes form the attribute group called "job-description".
Attribute Man
?
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job-URI Man
(uri)
job-originating- Man
user
(name)
job-originating-
host
(name)
user-locale
(type2 keyword)
job-state Man
(type1 keyword)
job-state-reasons Man
(1setOf type2
keyword)
job-state-message
(text)
output-device-
assigned
(name)
time-since- Man
submission
(milliseconds)
number-of- Man
intervening-jobs
(int)
job-message-from-
operator
(text)
time-since- Man
completion
(milliseconds)
job-k-octets-
completed
(int)
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job-impressions-
completed
(int)
job-media-sheets-
completed
(int)
6.3.2.1 job-URI (uri)
This attribute contains the URI for the job. The Printer, on receipt of
a new job, shall generate a URI which identifies the job on the Printer.
The Printer, shall return the value of the URI job attribute as part of
the PrintResult in the Print operation. The precise format of a job URI
shall be implementation dependent.
6.3.2.2 job-originating-user (name)
This attribute specifies the user name of the person submitting the
print job. The Printer shall set this attribute to the most authentic
name that it can obtain from the protocol over which the operation was
received from the client.
6.3.2.3 job-originating-host (name)
This attribute identifies the originating host of the job. The Printer
shall set this attribute to the most authentic host name it can obtain
from the protocol over which the operation was received from the
client.
6.3.2.4 user-locale (type3 keyword)
This attribute identifies the locale of the job, i.e, the country,
language, and coded character set. The Printer sets this attribute to
the most authentic value it can obtain from the protocol over which the
Print operation was received from the client.
The Printer shall use this attribute to determine the locale for
notification messages that it sends.
6.3.2.5 job-state (type1 keyword)
This attribute identifies the current state of the job.
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The Printer may provide additional information about each state value by
supplying one or more values of the job's companion "job-state-reasons"
attribute depending on implementation. While the job states cannot be
added to without impacting deployed clients that take actions upon
receiving job state values, it is the intent that additional "job-state-
reasons" values can be defined without impacting such deployed clients.
In other words, the "job-state-reasons" attribute is intended to be
extensible.
Standard values are:
unknown The job state is not known, or its
state is indeterminate.
pending The job is a candidate to start
processing, but is not yet
processing..
pending- The job is not a candidate for
stopped processing for any number of reasons
and will resume pending as soon as the
reasons are no longer present. The
job's "job-state-reason" attribute
shall indicate why the job is no
longer a candidate for processing.
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processing Either:
1. the job is using, or is attempting
to use, one or more document
transforms which include (1) purely
software processes that are
interpreting a PDL, and (2) hardware
devices that are interpreting a PDL,
making marks on a medium, and/or
performing finishing, such as stapling
OR
2. the server has made the job ready
for printing, but the output device is
not yet printing it, either because
the job hasn't reached the output
device or because the job is queued in
the output device or some other
spooler, awaiting the output device to
print it.
ISSUE: The "job-state-reasons"
specification is that the job is in
'pending' state not 'processing'
state.
When the job is in the 'processing'
state, the entire job state includes
the detailed status represented in the
printer's "printer-state", "printer-
state-reasons", and "printer-state-
message attributes.
Implementations may include additional
values in the job's "job-state-
reasons" attribute to indicate the
progress of the job, such as adding
the 'job-printing' value to indicate
when the output device is actually
making marks on paper. Most
implementations won't bother with this
nuance.
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processing The job has stopped while processing
-stopped for any number of reasons and will
continue processing as soon as the
reasons are no longer present. The
job's "job-state-reason" attribute
shall indicate why the job has stopped
processing.
If the output device is stopped, the
'printer-stopped' value shall be
included in the job's "job-state-
reasons" attribute. When the output
device is stopped, the device usually
indicates its condition in human
readable form locally at the device.
A client can obtain more complete
device status remotely by querying the
printer's "printer-state-reasons"
attribute.
canceled The job has been canceled by a Cancel-
Job operation and is either (1) in the
process of terminating or (2) has
completed terminating. The job's
"job-state-reasons" attribute shall
contain either the 'canceled-by-user'
or 'canceled-by-operator' value.
aborted The job has been aborted by the
system, usually while the job was in
the 'processing' state.
completed The job has completed successfully or
with warnings or errors and all of the
job media sheets have been properly
stacked in the appropriate output tray
or bin. The job's "job-state-reasons"
attribute shall contain one of:
'completed-successfully', 'completed-
with-warnings', or 'completed-with-
errors'.
The length of time that jobs remain in the 'canceled', 'aborted', and
'completed' states depends on implementation.
The following figure shows the normal job state transitions. Other
transitions are unlikely, but are not forbidden.
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+--> canceled
/
+----> pending --------> processing --+----> aborted
| ^ ^ \
----+ | | +--> completed
| v v
+----> pending-stopped processing-stopped
Figure 1 - Normal job state transitions
Normally a job progresses only from left to right through three states.
Even though the IPP protocol defines seven values for job states,
Printers SHALL only implement those states which are appropriate for the
particular implementation.
6.3.2.6 job-state-reasons (1setOf type2 keyword)
This attribute identifies the reason or reasons that the job is in the
state that it is in (e.g., 'pending', 'processing', 'completed', etc.).
The Printer shall indicate the particular reason(s) by setting the value
of the job's "job-state-reasons" attribute.
The following standard values are defined for use with the job states
indicated as applicable.
NOTE - For easy of understanding the order of the reasons is presented
in the normal order of job state progression:
none Mandatory: There are no reasons
for the job's current state.
Applicable job states:
'pending', 'processing',
'aborted'.
job-incoming Mandatory. The PrintJob or
CreateJob operation has been
accepted by the Printer, but the
Printer is waiting for additional
SendDocument operations and/or
the transfer of the remainder of
the job or document data.
Applicable job states: 'pending-
stopped'
job-outgoing Optional. The Printer is
transmitting the job to the
output device.
Applicable job states: 'pending'
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job-hold-until- Conditionally mandatory.
specified Mandatory if the "job-hold-until"
job attribute is implemented.
The value of the job's "job-hold-
until" attribute has specified a
time period that has not yet
arrived, so that the Printer
shall not consider the job as a
candidate for processing.
Applicable job states: 'pending-
stopped'.
job-hold-until- Optional. At least one of the
resources-are- resources needed by the job, such
ready as media, fonts, resource
objects, etc., is not ready on
any of the physical printer's for
which the job is a candidate.
Usually such a condition is
detected while the job is in the
'pending' state. If a job starts
processing and encounters a
resource that is not ready, there
are two possible implementations:
(1) the device is stopped and no
jobs can run until the
resource(s) are made ready, in
which case the Printer shall keep
the job in the 'processing' state
and shall add the 'printer-
stopped' reason to the job's
"job-state-reasons" attribute
(not the 'job-hold-until-
resources-are-ready' value) OR
(2) another job is found to use
the device while the current job
goes back to waiting for its turn
and for the resources to be made
ready, in which case the Printer
shall change the job's "job-
state" attribute to 'pending' and
add the 'job-hold-until-
resources-are-ready' value to the
job's "job-state-reasons"
attribute.
Applicable job states: 'pending-
stopped'.
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printer-stopped- Optional. This reason appears in
partly all jobs in the 'pending' state
when the value of the Printer's
"printer-state-reasons" attribute
contains the value 'stopped-
partly'.
Applicable job states: 'pending'
printer-stopped Mandatory. The output device is
stopped. This reason appears in
all jobs in the 'pending' and
'processing' states when the
value of the Printer's "printer-
state" attribute is 'stopped'.
Applicable job states: 'pending-
stopped', 'processing-stopped'
job-printing Optional. The output device is
marking media. This value is
useful for Printers which spend a
great deal of time processing
when no marking is happening and
then want to show that marking is
now happening.
Applicable job states:
'processing', 'processing-
stopped'
job-cancelled-by- Level 2 Mandatory. The job was
user cancelled by the user using the
CancelJob request.
Applicable job states:
'canceled'.
job-cancelled-by- Level 2 Mandatory. The job was
operator cancelled by the operator using
the CancelJob request.
Applicable job states:
'canceled'.
logfile-pending Optional. The job's logfile is
pending file transfer.
Applicable job states:
'canceled', 'aborted', and
'completed'.
logfile- Optional. The job's logfile is
transferring being transferred.
Applicable job states:
'canceled', 'aborted', and
'completed'.
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job-completed- Mandatory. The job completed
successfully successfully.
Applicable job states:
'completed'.
job-completed- Mandatory. The job completed
with-warnings with warnings.
Applicable job states:
'completed'.
job-completed- Mandatory. The job completed
with-errors with errors (and possibly
warnings too).
Applicable job states:
'completed'.
6.3.2.7 job-state-message (text)
This attributes specifies suplimental information about the Job State in
human readable text. It SHALL be set by the Printer.
6.3.2.8 output-device-assigned (uri)
This attribute identifies the Output Device to which the Printer has
assigned this job. If an output device implements an embedded IPP
Printer, the Printer NEED NOT set this attribute. If a Print Server
implements a Printer, the value MAY be empty until the Printer assigns
an output device to the job.
ISSUE: Why is this a uri?
6.3.2.9 time-since-submission (milliseconds)
This attribute indicates the amount of time that has passed since the
Job was first created.
6.3.2.10 time-since-processing (milliseconds)
This attribute indicates the amount of time that has passed since the
Job first entered the processing state.
6.3.2.11 number-of-intervening-jobs (integer(0:2**31 - 1))
This attribute indicates the number of jobs that are "ahead" of this job
in the current scheduled order. For efficiency, it is only necessary to
calculate this value when an operation if performed that requests this
attribute.
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Note: This attribute is necessary since an end user may request just
their own jobs and they need some relative position indicator if there
are other jobs interspersed in the waiting list which are not returned
in the response or cannot be because of site security policy
restrictions.
6.3.2.12 job-message-from-operator (text)
This attribute provides a message from an operator, system administrator
or "intelligent" process to indicate to the end user the reasons for
modification or other management action taken on a job.
6.3.2.13 time-since-completion (milliseconds)
This attribute indicates the amount of time that has passed since the
Job was first created.
6.3.2.14 job-k-octets-completed (integer(0:2**31 - 1))
This attribute specifies the number of octets completed in K octets,
i.e., in units of 1024 octets. The value shall be rounded up, so that a
job between 1 and 1024 octets shall be indicated as being 1K, 1025 to
2048 shall be 2, etc. This attribute is intended to be a counter as in
the Job Monitoring MIB.
6.3.2.15 job-impressions-completed (integer(0:2**31 - 1))
This job attribute specifies the number of impressions completed. This
attribute is intended to be a counter as in the Job Monitoring MIB.
6.3.2.16 job-media-sheets-completed (integer(0:2**31 - 1))
This job attribute specifies the media-sheets completed. This attribute
is intended to be a counter as in the Job Monitoring MIB.
6.4 Document Attributes
This group of attributes describes the document data for the job. They
are supplied in the Send-Document request.
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Attribute Man
?
document-name Man
(name)
document-format
(type2 keyword
document-URI
(uri)
6.4.1 document-name(name, Mandatory)
This attribute contains the name of the document used by the client to
initially identify the document. When a client prints by reference, i.e.
includes the document-URI attribute and no document content, this
attribute shall be absent. When a document's contents are spread across
multiple Send Document operations "document-name" is ignored by the
Printer in all but the first Send-Document operation.
6.4.2 document-format (type2 keyword)
This attribute defines the document format of this document. When a
client prints by reference, i.e. includes the document-URI attribute and
no document content, this attribute shall be absent. When a document's
contents are spread across multiple Send-Document operations, document-
format is ignored by the Printer in all but the first Send Document
operation for that document.
This attribute identifies the document format of this document. One
possible supported and default value is 'auto-sense'. However, 'auto-
sense' shall not be sent in the Send-Document Request.
The following standard values have been reviewed with the Printer
Working Group and are registered with IANA as part of the IETF Printer
MIB project. The standard value assigned by the PWG starts with the
four letters: "lang", in order to follow SNMP ASN.1 rules that all enum
symbols shall start with a lower case letter. The keyword values in IPP
shall be the same as the PWG standard values registered with IANA with
the "lang" removed. The MIB (integer) value is included here for
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reference only, the MIB integer value shall not be used in IPP; the
keyword value shall be used instead:
Note: In the protocol specification [22], these keywords will be
encoded as MIME types.
6.4.3 document-URI (uri)
This attribute contains the URI of the document when the document
content is not included in the Send Document operation. Document-number
is the only other attribute allowed when a document-URI attribute is
present in a Send Document operation.
6.5 Printer Attributes
The attributes in this section are associated with a Printer object.
6.5.1 Printer Job Template Attributes
The Job Template attributes which apply specifically to a Printer object
are described in section 6.2 Job Template Attributes.
These Printer attributes form the attribute group named "printer-job-
template".
6.5.2 Printer Description Attributes
These attributes form the attribute group called "printer-description".
A Printer object may be realized in either a print server or output
device. Note: How these attributes are set by an Administrator is
outside the scope of this specification.
Attribute Man?
printer-URI Man
(uri)
printer-name Man
(name)
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printer-location
(text)
printer-description
(text)
printer-more-info-
site
(uri)
printer-driver-
installer
(uri)
printer-make-and-
model
(text)
maximum-printer-
speed
(integerUnits)
printer-more-info-
manf
(uri)
printer-state Man
(type1 keyword)
printer-state- Man
reasons
(type2 keyword)
printer-is- Man
accepting-job
(boolean)s
printer-state-
message
(text)
queued-job-count
(int)
printer-message-
from-operator
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(text)
printer-locale Man
(locale)
printer-locales- Man
supported
(1setOf locale)
multiple-documents-
are-supported
(boolean)
6.5.2.1 printer-URI (uri)
This attribute contains the URI for the printer. An administrator shall
determine a printer's URI and shall set this attribute to that URI. The
precise format of a printer URI shall be implementation dependent.
6.5.2.2 printer-name (name)
This attribute contains the name of the printer. It is a name that is
more user friendly than the printer-URI. An administrator shall
determine a printer's name and shall set this attribute to that name.
This name may be the last part of the printer's URI or it may be
unrelated. In non-US-English locales, a name may contain characters that
are not allowed in a URI.
6.5.2.3 printer-location (text)
This attribute identifies the location of this printer.
6.5.2.4 printer-description (text)
This attribute identifies the descriptive information about the this
Printer. This could include things like: "This printer can be used for
printing color transparencies for HR presentations", or "Out of courtesy
for others, please print only small (1-5 page) jobs at this printer", or
even "This printer is going away on July 1, 1997, please find a new
printer".
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6.5.2.5 printer-more-info-site (uri)
This attribute contains a URI used to obtain more information about this
specific printer. The information obtained from this URI is intended
for end user consumption. Features outside the scope of IPP can be
accessed from this URI. The information is intended to be specific to
this printer instance and site services (e.g. job pricing, services
offered, end user assistance). The manufacturer may initially populate
this attribute.
6.5.2.6 printer-driver-installer (uri)
This attribute contains a URI to use to locate the driver installer for
this printer. This attribute is intended for consumption by automata.
The mechanics of print driver installation is outside the scope of IPP.
The manufacturer may initially populate this attribute.
6.5.2.7 printer-make-and-model (text)
This attribute identifies the make and model of the printer.
ISSUE: Several comments that we should break this up into two
attributes. It is just a text string, so it could really be anything.
6.5.2.8 maximum-printer-speed (integerUnits)
This attribute indicates the maximum printer speed of the Printer in
units of pages per minute, impressions per minute, lines per minute, and
characters per second. A job cannot control a Printer's speed, but a
Printer Browser can use printer speed as a criteria.
The standard units are a type2 setOf keyword : ppm, ipm, spm, lpm, and
cps. These mean pages per minute, impressions per minutes, sides per
minutes, lines per minute, and characters-per-second, respectively.
6.5.2.9 printer-more-info-manf (uri)
This attribute contains a URI used to obtain more information about this
type of printer. The information obtained from this URI is intended for
end user consumption. Features outside the scope of IPP can be accessed
from this URI (e.g., latest firmware, upgrades, print drivers, optional
features available). The information is intended to be germane to this
printer without regard to site specific modifications or services.
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6.5.2.10 printer-state (type1 keyword)
This attribute identifies the current state of the printer. The
printer-state reasons attribute augments the printer-state attribute to
give more detailed information about the Printer is in the given printer
state.
The protocol shall support all values for printer states. A Printer
shall continually keep this attribute set to the value in the table
below which most accurately reflects the state of the Printer.
The following standard values are defined:
unknown The Printer state is not known, or is
indeterminate. A Printer shall use
this state only if it cannot
determine its actual state.
idle If a Printer receives a job (whose
required resources are ready) while
in this state, such a job shall
transit into the processing state
immediately.
If the printer-state-reasons
attribute contains any reasons, they
shall be reasons that would not
prevent a job from transiting into
the processing state immediately,
e.g., toner-low.
Note: if a Printer controls more than
one output device, the above
definition implies that a Printer is
idle if at least one output device is
idle.
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processing If a Printer receives a job (whose
required resources are ready) while
in this state, such a job shall
transit into the pending state
immediately. Such a job shall transit
into the processing state only after
jobs ahead of it complete printing.
If the printer-state-reasons
attribute contains any reasons, they
shall be reasons that do not prevent
the current job from printing, e.g.
toner-low.
Note: if a Printer controls more than
one output device, the above
definition implies that a Printer is
processing if at least one output
device is processing, and none is
idle.
stopped If a Printer receives a job (whose
required resources are ready) while
in this state, such a job shall
transit into the pending state
immediately. Such a job shall transit
into the processing state only after
some human fixes the problem that
stopped the printer and after jobs
ahead of it complete printing.
The printer-state-reasons attribute
shall contain at least one reason,
e.g. paper-jam, which prevents it
from either processing the current
job or transiting a pending job to
the processing state.
Note: if a Printer controls more than
one output device, the above
definition implies that a Printer is
stopped only if all output devices
are stopped.
Note: In the case where a Printer controls more than one output device,
it is tempting to define stopped as when a sufficient number of output
devices are stopped and leave it to an implementation to define the
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sufficient number. But such a rule complicates the definition of
stopped and processing. For example, with this alternate definition of
stopped, a job can move from idle to processing without human
intervention, even though the Printer is stopped.
6.5.2.11 printer-state-reasons (1setOf type2 keyword)
This attribute supplies additional detail about the printer's state.
Each value shall have an adornment to indicate its level of severity.
The three levels are: report (least severe), warning and error (most
severe).
- 'report': it has the adornment of "report". An implementation may
choose to omit some or all reports. Some reports specify finer
granularity about the printer state; others serve as a precursor to
a warning. A report shall contain nothing that could affect the
printed output.
- 'warning': it has the adornment of "warning". An implementation may
choose to omit some or all warnings. Warnings serve as a precursor
to an error. A warning shall contain nothing that prevents a job
from completing, though in some cases the output may be of lower
quality.
- 'error': it has no adornment. An implementation shall include all
errors. If this attribute contains one or more errors, printer
shall be in the stopped state.
ISSUE: How do we indicate report, warning, or error without adornments?
Proposal add a parallel attribute to print-state-reasons and name it
"printer-state-reasons-severity-level". The ith element of the reasons
attribute has the severity level of the ith element of the severity
level attribute. Another proposal: an implementation may add 'error-',
'warning-', or 'report-' to any of the reasons to indicate the level of
severity.
ISSUE: Toner-low should be a warning because it allows printing to
proceed, but in some printers, toner-low may also produce degraded
output. Do we want a fourth category, perhaps severe-warning which
allows a job to continue printing but with reduced quality?
If a Printer controls more than one output device, each value of this
attribute shall apply to one more of the output devices. An error on one
output device that does not stop the Printer as a whole appears as a
warning in the Printer's printer-state-reasons attribute. Such a
Printer's printer-state value may be stopped even with no printer-state-
reasons that are errors.
The following standard values are defined:
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stopped-partly When a Printer controls more than
one output device, this reason
indicates that one or more output
devices are stopped. If the
reason is a report, fewer than
half of the output devices are
stopped. If the reason is a
warning, fewer than all of the
output devices are stopped.
media-needed A tray has run out of media
paper-jam The printer has a paper jam.
paused Someone has paused the Printer.
In this state, a Printer shall
not produce printed output, but
it shall perform other operations
requested by a client. If a
Printer had been printing a job
when the Printer was paused, the
Printer shall resume printing
that job when the Printer is no
longer paused and leave no
evidence in the printed output of
such a pause .
shutdown Someone has removed a Printer
from service, and it may be
powered down or physical removed.
In this state, a Printer shall
not produce printed output, and
unless the Printer is realized by
a print server that is still
active, the Printer shall perform
no other operations requested by
a client, including returning
this value. If a Printer had been
printing a job when it was
shutdown, the Printer need not
resume printing that job when the
Printer is no longer shutdown. If
the Printer resumes printing such
a job, it may leave evidence in
the printed output of such a
shutdown, e.g. the part printed
before the shutdown may be
printed a second time after the
shutdown..
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connecting-to- The server has scheduled a job on
printer the Printer and is in the process
of connecting to a shared network
output device (and might not be
able to actually start printing
the job for an arbitrarily long
time depending on the usage of
the output device by other
servers on the network).
timed-out The server was able to connect to
the output device (or is always
connected), but was unable to get
a response from the output device
in the time specified by the
printer's printer-timeout-period
attribute.
stopping The printer will be stopping in a
while and will change its reason
to printer-stopped. This reason
is a non-critical, even for a
Printer with a single output
device. When an output-device
ceases accepting jobs, the
Printer will have this state
while the output device completes
printing.
6.5.2.12 printer-is-accepting-jobs (boolean)
This attribute determines whether the printer is currently accepting
job. If the value is true, the printer is accepting jobs. If the value
is false, the printer is currently rejecting any jobs submitted to it.
Note: This value is independent of the printer state and printer-state-
reasons because its value does not affect the current job; rather it
affects future jobs. This attribute may cause the Printer to reject jobs
when the printer-state is idle or it may cause the Printer to accepts
jobs when the printer-state is stopped.
6.5.2.13 printer-state-message (text)
This attribute specifies the additional informaion about the printer
state in human readable text and it shall be set by the Printer (or the
Administrator by some mechanism outside the scope of IPP). When a
Printer returns the value of this attribute to a client, the Printer
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shall localize the value of this attribute to be in the locale of the
user, as specified by the Get-Attributes or Get-Jobs operation.
6.5.2.14 queued-job-count (integer(0:2**31 - 1))
This attribute contains a count of the number of jobs that are either
pending and/or processing and shall be set by the Printer.
6.5.2.15 printer-message-from-the-operator (text)
This attribute provides a message from an operator, system administrator
or "intelligent" process to indicate to the end user information or
status of the printer, such as why it is unavailable or when it is
expected to be available.
6.5.2.16 printer-locale (locale)
This attribute specifies the current locale that the Printer is
operating in.
6.5.2.17 printer-locales-supported (1setOf locale)
This attribute specifies the locales that the Printer operates in.
7. Conformance
This section describes conformance issues and requirements. This
document introduces model entities such as objects, operations,
attributes, and attribute values. These conformance sections
describe the conformance requirements which apply to these model
entities.
7.1 Conditionally Mandatory
For example, a conditionally mandatory attribute means that a Printer
implementation need not implement the attribute if the attribute
controls a feature that the output device does not implement or
expose. For example, for an output device that can only print on one
side, a Printer need not implement the "sides" attribute. For an
output device that does not support any of the finishing attribute
values, a Printer need not implement the "finishing" attribute. An
implementation that does not allow for 'not-ready' supported values
in addition to 'ready' values, need not implement the corresponding
"xxx-availability" Printer attribute. For an output device with only
a single input tray with only one media type in that tray, a Printer
need not implement the "media" attribute.
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7.2 Client Conformance Requirements
There are no conformance requirements placed on the user interfaces
provided by IPP clients or their applications. For example, one
application might not allow an end user to submit multiple documents
per job, while another does. One application might first query a
Printer object in order to supply a graphical user interface (GUI)
dialogue box with supported and default values whereas a different
application might not.
When sending a Get-Attributes or Create-Job request, an IPP client
need not supply any attributes.
A client shall be able to accept any of the attribute syntaxes
defined in Section 0 that may be returned to it in a response from a
Printer
ISSUE: Are there any attributes that are mandatory for a client to
set in a Print request?
A query response may contain attributes and values that the client
does not implement or expect. Therefore, a client implementation
must gracefully handle such responses and not refuse to interoperate
with a conforming Printer that is returning extended registered or
private attributes and/or attribute values that conform to Section 8.
IANA Considerations, Registered Extensions, Private
Extensions. Some clients may choose to ignore any attributes that it
does not implement.
7.3 Printer Object Conformance Requirements
This section specifies the conformance requirements for conforming
Printer object implementations with respect to objects, operations,
and attributes.
7.3.1 Objects
Conforming Printer implementations shall implement all of the model
objects as defined in this specification in the indicated sections:
Section 0 4.1 Printer Object
Section 0 4.2 Job Object
Section 0 4.3 Document Object
7.3.2 Operations
Conforming Printer implementations shall implement all of the model
operations, including mandatory responses, as defined in this
specification in the indicated sections:
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Section 0
Section Job 0 5.1.4 Cancel Job Operation
Section 0 5.1.5 Get-Attributes Operation
Section 0 5.1.6 Get-Jobs Operation
7.3.3 Attributes
ISSUE: Some Printer attributes are purely software, so that
Conditionally Mandatory doesn't apply, such as Printer Description
Attributes. For example, what does it mean for the "printer-
location" to be Conditionally Mandatory? Should we add a "OPTIONAL"
in the header of the few attributes for which Conditionally Mandatory
doesn't make sense?
Conforming Printer implementations shall implement all of the
mandatory attributes, as defined in this specification in the
indicated sections. Mandatory attributes are indicated as
"MANDATORY" in the header of each sub-section of Section 0 that
specifies the attribute which is copied into the Table of Contents:
ISSUE: What if this list differs from the headers, which wins?
Wouldn't it be safer and more compact to replace the above list with
a reference to section 6 attributes that are flagged as MANDATORY in
the header line (and automatically copied to the Table of Contents)?
Conforming Printer implementations shall implement all conditionally
mandatory attributes in Section 0, i.e., the additional Job and
Printer attributes that represent features that the output device
implements.
It is not required that a conforming Printer implement or support all
values of all implemented attributes. For example, if a Printer
supports some of the "finishing" attribute values in this document,
it is not required that a Printer implement or support all finishing
methods indicated by all the values of the "finishing" attribute
contained in this document.
If a Printer implements a "xxx-supported" attribute it must implement
the corresponding "xxx" default value attribute and vice versa.
7.3.4 Default Value
If the output device itself does not support the concept of a default
value or the output device's default value is unpredictable, or
unknown, the implementation of the Printer shall always supply its
default value to the physical device each time the Printer submits
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the job to the output device. The default value specified by a
Printer shall not be 'unknown'.
7.3.5 Availability
Conforming implementation need not implement the "xxx-available"
attributes since if an "xxx-supported" printer attribute does not
have have an associated "xxx-available" Printer attribute, all
supported values shall be 'ready'.
7.3.6 Printer extensions
A conforming Printer may implement registered extensions and private
extensions, as long as they meet the requirements specified in
Section 8. IANA Considerations, Registered Extensions, Private
Extensions.
7.3.7 Attribute Syntaxes
A Printer shall be able to accept any of the attribute syntaxes
defined in Section 0 in any operation in which a client may supply
attributes. Furthermore, a Printer shall return attributes to the
client in operation responses that conform to the syntax specified in
Section 0.
7.4 Security Conformance Requirements
The security mechanisms being considered for IPP fall outside the
scope of the application layer protocol itself. There are two
mechanisms used to begin secure communications using IPP:
1. Information in the directory entry for an IPP Printer (or from
additional information at a Web site hosting the IPP Priner) indicate
which, if any, security protocols are used in conjunction with IPP.
2. The URI for the IPP Printer contains the security protocol
information (https://..., etc.)
In either case, the security protocol (if any) is initiated first
which allows for the negotiation of security features. IPP is then
run as an application protocol on top of the security protocols. One
cannot "bootstrap" the security features from IPP itself.
8. IANA Considerations, Registered Extensions, Private Extensions
IPP is explicitly designed to be extensible. Additional attributes
can be proposed to be registered by going through the type 2 or type
3 keyword process which will register their specification after
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approval with IANA. In addition specific implementation instances
may support not only the basic protocol as defined in this
specification, but may add vendor-specific private extensions by
prefixing attribute-names with their company name registered with
IANA for use in domains. See attribute syntax section. However,
such private extensions shall not duplicate attribute semantics
already in this specification.
9. Security Considerations
There is another Internet-Draft called "Internet Printing
Protocol/1.0: Security" [22]. That document is being drafted and
reviewed in parallel with this document. The mapping of IPP on top
of appropriate security protocols will be described in that document.
IPP does not introduce any new, general purpose security mechanisms
for authentication and encryption.
A Printer may choose, for security reasons, not to return all
attributes that a client requests. It may even return none of the
requested attributes. In such cases, the status returned is the same
as if the Printer had returned all requested attributes. The client
cannot tell by such a response whether the requested attribute was
present or absent on the Printer.
10. References
[1] Smith, R., Wright, F., Hastings, T., Zilles, S., and Gyllenskog,
J., "Printer MIB", RFC 1759, March 1995.
[2] Berners-Lee, T, Fielding, R., and Nielsen, H., "Hypertext Transfer
Protocol - HTTP/1.0", RFC 1945, August 1995.
[3] Crocker, D., "Standard for the Format of ARPA Internet Text
Messages", RFC 822, August 1982.
[4] Postel, J., "Instructions to RFC Authors", RFC 1543, October 1993.
[5] ISO/IEC 10175 Document Printing Application (DPA), Final, June
1996.
[6] Herriot, R. (editor), X/Open A Printing System Interoperability
Specification (PSIS), August 1995.
[7] Kirk, M. (editor), POSIX System Administration - Part 4: Printing
Interfaces, POSIX 1387.4 D8, 1994.
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[8] Borenstein, N., and Freed, N., "MIME (Multi-purpose Internet Mail
Extensions) Part One: Mechanism for Specifying and Describing the
Format of Internet Message Bodies", RFC 1521, September, 1993.
[9] Braden, S., "Requirements for Internet Hosts - Application and
Support", RFC 1123, October, 1989,
[10] McLaughlin, L. III, (editor), "Line Printer Daemon Protocol" RFC
1179, August 1990.
[11] Berners-Lee, T., Masinter, L., McCahill, M. , "Uniform Resource
Locators (URL)", RFC 1738, December, 1994.
[20] Internet Printing Protocol: Requirements
[21] Internet Printing Protocol/1.0: Model and Semantics (This document)
[22] Internet Printing Protocol/1.0: Security
[23] Internet Printing Protocol/1.0: Protocol Specification
[24] Internet Printing Protocol/1.0: Directory Schema
[25] S. Bradner, "Key words for use in RFCs to Indicate Requirement
Levels", RFC 2119 , March 1997
11. Author's Address
Scott A. Isaacson
Novell, Inc.
122 E 1700 S
Provo, UT 84606
Phone: 801-861-7366
Fax: 801-861-4025
EMail: scott_isaacson@novell.com
Tom Hastings
Xerox Corporation
701 S. Aviation Blvd.
El Segundo, CA 90245
Phone: 310-333-6413
Fax: 310-333-5514
EMail: hastings@cp10.es.xerox.com
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Robert Herriot
Sun Microsystems Inc.
2550 Garcia Ave., MPK-17
Mountain View, CA 94043
Phone: 415-786-8995
Fax: 415-786-7077
Email: robert.herriot@eng.sun.com
Roger deBry
HUC/003G
IBM Corporation
P.O. Box 1900
Boulder, CO 80301-9191
Phone: (303) 924-4080
Fax: (303) 924-9889
Email: debry@vnet.ibm.com
Patrick Powell
San Diego State University
9475 Chesapeake Dr. Suite D
San Diego, CA 92123
Phone: (619) 874-6543
Fax: (619) 279-8424
Email: papowell@sdsu.edu
IPP Mailing List: ipp@pwg.org
IPP Mailing List Subscription: ipp-request@pwg.org
IPP Web Page: http://www.pwg.org/ipp/
Other Participants:
Chuck Adams - Tektronix
Jeff Barnett - IBM
Ron Bergman - Data Products
Keith Carter, IBM Corporation
Jeff Copeland - QMS
Andy Davidson - Tektronix
Mabry Dozier - QMS
Lee Farrell - Canon Information Systems
Steve Gebert - IBM
David Kellerman - Northlake Software
Rick Landau - Digital
Harry Lewis - IBM
Pete Loya - HP
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Ray Lutz - Cognisys
Mike MacKay, Novell, Inc.
Carl-Uno Manros, Xerox, Corp.
Jay Martin - Underscore
Stan McConnell - Xerox
Pat Nogay - IBM
Bob Pentecost - HP
Rob Rhoads - Intel
David Roach - Unisys
Hiroyuki Sato - Canon
Bob Setterbo - Adobe
Devon Taylor, Novell, Inc.
Mike Timperman - Lexmark
Randy Turner - Sharp
Atsushi Yuki - Kyocera
Lloyd Young - Lexmark
Bill Wagner - DPI
Jim Walker - DAZEL
Chris Wellens - Interworking Labs
Rob Whittle - Novell
Don Wright - Lexmark
Peter Zehler, Xerox, Corp.
12.
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Change History
This section will be deleted when the document is forwarded to the
IESG to be considered for becoming an RFC. The changes are
summarized in reverse chronological order.
12.1 Changes made to version 970512, dated 12-May-1997 to make version
970603, dated 03-June-1997.
1. Removed the idea of "default beahvior"
2. Removed the idea of "best-effort" 'substitute-as-needed' and 'do-not-
substitute'
3. Deleted all of the definitions from section 3 and changed the figures
4. Added references to RFC 2119 (standard conformance language) and
started to capitalize all of the implementation requirement words such
as SHALL, NEED NOT, MUST, etc.
5. Removed font Printer attributes and scheduling algorithm
6. Reformated all the of 6.2 (Job Template)
7. Consolidated the 3 sections on Job Template down into just one
section.
8. Added attribute tables to be beginning of each first level section in
6.0. These tables show attribute name, syntax, and MAND/OPT/etc.
9. Fixed the definitions for Implements and Supports
10. Added Create-Job, Print-Job, and Send-Document operations
11. Reformatted the whole Operations section
12. Reformatted most of the standard values sections for keyword
attributes. This needs to be finished for the next rev of the document.
13. Changed URL to URI.
12.2 Changes made to version 970509, dated 9-May-1997 to make version
970512, dated 12-May-1997.
1. Replaced Print with Create-Job and Send-Document
2. Added status codes (ok, error, and messages)
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3. Removed all "may not" language (replace with might not)
4. Fixed attribute sections to show more detail
5. Misc. typos and edits
12.3 Changes made to version 2.2, dated 5-May-1997 to make version
970509, dated 9-May-1997.
1.
Too many to mention.
12.4 Changes made to version 2.1, dated 24-April-1997 to make version
2.2, dated 5-May-1997.
Added terminology to the conformance section for keyword, attribute,
attribute name, attribute value(s), default, default behavior,
availabilty.
Removed most discussion about adornments and tags, except for
embedded tag and job-state-reasons, report, warning, error tags.
Moved Conformance description to the appropriate operation sections,
so that the Conformance section is a checklist with references to the
sections where the semantics are described.
Changed the job-size attributes into xxx-requested, xxx-completed Job
attributes, and xxx-supported Printer attributes.
12.5 Changes made to version 2.0, dated 26-March-1997 to make version
2.1, dated 22-April-1997.
1.
Added terminology to the conformance section for supported and
implemented.
12.6 Changes made to version 1.8, dated 24-March-1997 to make version
2.0, dated 26-March-1997.
The following changes were made to version 1.8 to make version 2.0:
1. Minor editing fixes
2. Submitted 2.0 as draft-ietf-ipp-model-00.txt
12.7 Changes made to version 1.7, dated 24-Mar-1997 to make version 1.8,
dated 24-March-1997.
The following changes were made to version 1.7 to make version 1.8:
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1. Minor editing fixes
12.8 Changes made to version 1.6, dated 12-Mar-1997 to make version 1.7,
dated 24-March-1997.
The following changes were made to version 1.6 to make version 1.7:
1. Removed Text Handling attributes
2. Removed best-effort tag, added best-effort Job attribute
3. Moved job-name from Job Template to Job Identification
4. Fixed many typos, spelling errors, etc.
5. Removed enum and added keyword
6. Print Response returns Job Status not Printer Status (since Job
status includes interesting Printer
Status)
7. Removed file type, added format to Get-Attributes
8. Added Patrick Powell as author
9. Move conformance to section 1, added client and server
considerations
10. Added a IANA considerations section
11. Added a type4 keyword
12. Removed the notion of "secondary tags"
13. Added more section headers
14. Merged the Job Production Attributes and Document Production
Attributes section
12.9 Changes made to version 1.5, dated 11-Mar-1997 to make version 1.6,
dated 12-March-1997.
The following changes were made to version 1.5, dated 11-Feb-1997 to
make version 1.6, dated 12-March-1997 from the miscellaneous e-mail
messages, suggestions, and agreements:
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1.
Added a new abstract with includes a reference to other IPP
documents
2.
Added Roger deBry's "new intro" document.
3.
Added a modified text diagram showing IPP mapped onto a generic
distributed printing model in section 2.0
4.
Added some new summary and introductory comments to 2.0 to clarify
that this section is not only meant to introduce the IPP model but
to show a mapping onto the various architecture and product
solutions on which IPP will be implemented.
5.
Added a new section (3.4) summarizing the role of object attributes
and introduced the notion of Job Template (Printer and Job)
attributes along with "adornments"
6.
Fixed up section 3.3 on Object relationships.
7.
Fixed Section 3.5 on object identity. This section now shows that
Jobs and Printers have both URLs and Names. Documents have Names
and Ids
8.
Added the correct references to Printer attributes in section 3.1
9.
Fixed the references to Job attributes in section 3.2
10.
Added a high level over view of the IPP operations and their
purpose and interactions to section 4.1 (Roger deBry worked on this
section)
11.
Replaced the security section with a reference to a new IPP
Security document which will eventually be merged back into this
document
12.
In section 5.2 I added subheading for each attribute to more
easily locate the text associated with the attribute as a Job
object attribute and then the text associated with the attribute as
a Printer object attribute.
13.
Reorganized section 3 to include a Document object.
14.
Added IPP Mailing list info to contact list
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12.10 Changes made to version 1.4, dated 27-Feb-1997 to make version
1.5, dated 9-March-1997.
The following changes were made to version 1.4, dated 27-Feb-1997 to
make version 1.5, dated 9-March-1997 from the 3/6/97 telecon
agreements:
1.
Replaced the data types with the ones discussed on the 3/6/97
telecon. Added back octetString, type1Enum, type2Enum, type3Enum
types as well.
2.
Added range constraints to the integer data type.
3.
Changed the xxx-locale attributes to be type3Enum.
4.
Added standard printer-resolution enum values.
5.
Added standard document-format enum values from the Printer MIB and
IANA registries.
6.
Added back job-hold-until attribute using named periods only and
added back the job-hold-until-specified value to the job-state-
reasons attribute.
7.
Changed the job state from printing to processing to agree with the
Printer state and changed the optional job-processing job-state-
reasons value to job-printing for use with Printers that take a lot
of time processing while not marking.
8.
Deleted the second occurrence of the job-name attribute, since we
removed any attributes that are common to both Job and Printer.
9.
Changed job-priority from a type1Enum to integer(1:100) so as to
have more levels so as to be able to match existing systems.
10.
Changed job-retention-period to use integerSeconds, instead of
minutes.
11.
Changed the Text Formatting attributes to take only the computer
points as units.
12.
Changed job-octets to job-K-octets, in order to be able to print
large documents. Aligns with the IETF Job Monitoring MIB.
13.
Clarified that the job-incomplete value of job-state-reasons is
waiting for document data, as opposed waiting for the job to be
closed.
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