Network Working Group H. Sugano
INTERNET-DRAFT S. Fujimoto
Fujitsu
G. Klyne
Baltimore Technologies
A. Bateman
VisionTech
Expires: September 2002 March 2002
CPIM Presence Information Data Format
<draft-ietf-impp-cpim-pidf-02.txt>
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
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Please send comments to the authors or to the impp@iastate.edu
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Copyright Notice
Copyright (C) The Internet Society (2002). All Rights Reserved.
Abstract
This memo specifies CPIM Presence Information Data Format (PIDF) as a
common presence data format for CPIM-compliant IM/Presence protocols.
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Table of Content
1. Introduction ......................................... 3
1.1. Terminology and Conventions .......................... 3
2. Design Decisions ..................................... 4
2.1. Minimal Model ........................................ 4
2.2. Added Features ....................................... 5
2.3. Encoding Decisions ................................... 5
2.3.1. Adoption of XML ...................................... 5
2.3.2. Combining Multiple Presence Documents ................ 5
3. Overview of Presence Information Data Format ......... 5
3.1. The 'application/cpim-pidf+xml' Content Type ......... 5
3.2. Presence Information Contents ........................ 6
3.3. Using Multipart Entity ............................... 6
4. XML-encoded Presence Data Format ..................... 6
4.1. XML Format Definitions ............................... 7
4.1.1. The <presence> element ............................... 7
4.1.2. The <presentity> element ............................. 7
4.1.3. The <tuple> element .................................. 7
4.1.4. The <status> element ................................. 7
4.1.5. The <value> element .................................. 8
4.1.6. The <contact> element ................................ 8
4.1.7. The <note> element ................................... 8
4.1.8. The <timestamp> element .............................. 9
4.2. Presence Information Extensibility ................... 9
4.2.1. XML Namespaces Background ............................ 9
4.2.2. XML Namespaces In Presence Information ............... 10
4.2.3. Handling Of Unrecognized Element Names ............... 10
4.3. Examples ............................................. 11
4.3.1. Default Namespace And No Extensions .................. 11
4.3.2. Example Presence Information Extensions .............. 12
4.3.3. Example Mandatory To Understand Extensions ........... 12
4.4. DTD .................................................. 13
5. Wrapping 'application/cpim-pidf+xml' Data ............ 14
5.1. When Used With 'message/cpim' ........................ 14
5.1.1. The 'From' header .................................... 14
5.1.2. The 'To' header ...................................... 14
5.1.3. The 'DateTime' header ................................ 14
5.1.4. The 'NS' header ...................................... 14
5.1.5. The 'Require' header ................................. 15
5.2. When Used With 'multipart/mixed' ..................... 15
5.2.1. The 'Presence-Data-ID' header ........................ 15
5.3. Examples ............................................. 15
6. Security Considerations .............................. 16
7. IANA Considerations .................................. 17
8. References ........................................... 17
9. Author's Addresses ................................... 18
10. Full Copyright Statement ............................ 19
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1. Introduction
The Common Profile for Instant Messaging (CPIM) specifications define
a set of common operations and various formats to achieve
interoperability between different Instant Messaging and Presence
protocols which meet RFC 2779 [RFC2779]. The CPIM core specification
[CPIM] defines a set of common operations and their parameters to be
supported by interworking Presence and IM protocols in order to allow
straightforward gatewaying between them. The work on CPIM Message
Format [CPIM-MSG] defines a common format for instant messages, which
enables secure end-to-end IM exchange through the gateways.
This memo further defines the CPIM Presence Information Data Format
(PIDF) as a common presence data format for CPIM-compliant presence
protocols. The significance of the common presence format primarily
resides in the fact that it alleviates the load of gatewaying of
messages with presence data payloads. Without such a common presence
data format, a gateway must process and transform the presence data
payload from one format to another every time it gateways the
protocol messages. Such payload processing aslo disable the validity
of digitally signed presence data. Utilizing the common presence
data format allows secure transfer of the presence payloads across
the boundary of different protocol domains.
The format specified in this memo is intended to define the base
presence format and extensibility required by RFC 2779. It only
defines a minimal set of presence status values defined by the IMPP
Model document [RFC2778]. However, a presence application is able to
define its own status values using the extensibility framework
provided by this memo. Defining such extended status values is
beyond the scope of this memo.
1.1. Terminology and Conventions
This memo makes use of the vocabulary defined in the IMPP Model
document [RFC2778]. Terms such as CLOSED, INSTANT MESSAGE, OPEN,
PRESENCE SERVICE, PRESENTITY, WATCHER, and WATCHER USER AGENT in the
memo are used in the same meaning as defined therein.
The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",
"RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be
interpreted as described in RFC 2119 [RFC2119].
[[[Editorial comments and questions about outstanding issues are
provided in triple brackets like this. These working comments should
be resolved and removed prior to final publication.]]]
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2. Design Decisions
We have adopted the IMPP Model and Requirements documents [RFC2778,
RFC2779] as the starting point of our discussion. The two RFCs
contains some statements about presence information, which can be
regarded as a basic set of constraints for the format design. Also,
we took the minimalist approach to the design based on them.
Starting from the minimal model, only the features that are necessary
to solve particular problems were combined.
2.1. Minimal Model
This specification is based on the minimal model extracted from the
IMPP Model and Requirements documents. The model consists of the
following items. Each of them is accompanied with the corresponding
RFCs and their section numbers as its gounds, e.g. (RFC2778:Sec.2.4)
refers to Section 2.4 of RFC 2778.
(a) PRESENCE INFORMATION consists of one or more PRESENCE TUPLES,
where a PRESENCE TUPLE consists of a STATUS, an optional
COMMUNICATION ADDRESS, and optional OTHER PRESENCE MARKUP.
(RFC2778:Sec.3)
(b) STATUS has at least the mutually-exclusive values OPEN and
CLOSED, which have meaning for the acceptance of INSTANT
MESSAGES, and may have meaning for other COMMUNICATION MEANS.
There may be other values of STATUS that do not imply anything
about INSTANT MESSAGE acceptance. These other values of STATUS
may be combined with OPEN and CLOSED or they may be mutually-
exclusive with those values. (RFC2778:Sec.3, RFC2779:Sec.4.4.1-
4.4.3)
(c) STATUS may consist of single or multiple values. (RFC2778:Sec.2.4)
(d) There must be a means of extending the common presence format
to represent additional information not included in the common
format. The extension and registration mechanisms must be
defined for presence information schema, including new STATUS
conditions and new forms for OTHER PRESENCE MARKUP. (RFC2779:
Sec.3.1.4-3.1.5)
(e) The common presence format must include a means to uniquely
identify the PRESENTITY whose PRESENCE INFORMATION is reported.
(RFC2779:Sec.3.1.2)
(f) The common presence format must allow the source of the presence
data (i.e. PRESENTITY) to utilize some security mechanism (e.g.
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digital signature or encryption) for the secure transportation
of the data. (RFC2779:Sec.5.2.1, 5.3.1, 5.3.3)
(g) The common presence format must be extensible to represent
additional information not defined in this memo. (RFC2779:
Sec.3.1.4)
2.2. Added Features
In addition to the minimal model described above, the format
specified in this specification has the following extra features.
[TBD: Needs more explanations]
(a) Relative priorities of contact addresses.
(b) Timestamping
2.3. Encoding Decisions
2.3.1. Adoption of XML
The CPIM Presence Information Data Format encodes presence
information in XML (eXtensible Markup Language [XML]). Because XML
provides an excellent framework to contain structured data such as
PRESENCE INFORMATION and inherently extensible, it is supposed to be
more desirable for our purpose than other format such as vCard.
[TBD]
2.3.2. Combining Multiple Presence Documents
If a presence service needs to combine multiple presence documents as
opaque data, i.e. without processing the XML contents, in a single
notification message, the MIME multipart entity is used. The reason
for using MIME multipart comes from an architectural consideration
such that each component presence document may come from different
sources and it might be secured with a MIME security mechanism by the
presence source.
3. Overview of Presence Information Data Format
This section describes an overview of the presence data format
defined in this memo.
3.1. The 'application/cpim-pidf+xml' Content Type
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This memo defines a new content type "application/cpim-pidf+xml" to
contain an XML-encoded presence information document which conforms
to this specification.
The content type "application/cpim-pidf+xml" MAY have a "charset"
parameter to indicate the character set and its encoding used in the
body. If no "charset" is specified, the application MUST treat the
body as "UTF-8" encoded.
3.2. Presence Information Contents
This subsection outlines types of information included in an
"application/cpim-pidf+xml" type document. The real definition of the
content type will be presented in Section 4.
o PRESENTITY URL: specifies the "pres" URL of the PRESENTITY.
o List of presence tuples
- Status: OPEN/CLOSED for Instant Messaging or status for
other communication means.
- Communication address: communication means and contact
address of this tuple. (optional)
- Relative priority: numerical value specifying the priority
of this communication address. (optional)
- Timestamp: timestamp of the change of this tuple.(optional)
- Human readable comment: free text memo about this tuple
(optional)
o PRESENTITY human readable comment: free text memo about the
PRESENTITY (optional).
3.3. Using Multipart Entity
For the purpose of combining multiple presence documents as opaque
data, the "multipart/mixed" content type MUST be used. Each part of
the multipart entity itself SHOULD be an "application/cpim-pidf+xml"
type MIME entity or a signed or encrypted MIME entity using the MIME
security multiparts in conjunction with an appropriate security
scheme. Section 5.2 describes the usage of the "multipart/mixed"
content type to convey multiple presence documents.
4. XML-encoded Presence Data Format
This section defines an XML-encoded presence data format of the
content type "application/cpim-pidf+xml" for presence payloads. A
presence payload of this type is expected to be produced by the
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PRESENTITY (the source of the PRESENCE INFORMATION) and transported
to the WATCHERS by the presence servers or gateways without any
interpretation or modification.
4.1. XML Format Definitions
An "application/cpim-pidf+xml" object is a well formed XML document.
4.1.1. The <presence> element
The root element of the "application/cpim-pidf+xml" object is defined
as <presence>. This element contains one <presentity> element, one
or more <tuple> elements, and an OPTIONAL <note> element.
The <presence> element SHOULD contain an 'xmlns' attribute to
indicate the namespace of the version of the presence document. The
presence document compliant to this specification MUST have the
namespace 'urn:ietf:params:cpim-presence:'.
4.1.2. The <presentity> element
The <presentity> element MUST have an 'id' attribute and has no
content. The value of the 'id' attribute is the 'pres' URL of the
PRESENTITY publishing this PRESENCE INFORMATION.
4.1.3. The <tuple> element
The <tuple> element is used to carry a piece of PRESENCE INFORMATION
defined as PRESENCE TUPLE in RFC2778. Thus, it contains a mandatory
<status> element and OPTIONAL <contact>, <note>, and <timestamp>
elements.
The <tuple> element MUST contain an 'id' attribute which is used to
distinguish this tuple from other tuples in the same XML document.
The value of an 'id' attribute MUST be a CDATA value, and MUST be
unique within 'id' attribute values of other tuples in the same
document. An 'id' value is used by applications processing the
presence document to identify the corresponding tuple in the
previously acquired PRESENCE INFORMATION of the same PRESENTITY.
The reason the <contact> element is OPTIONAL is that there is a case
a PRESENTITY might need to hide its communication address or there
might be tuples not related to any communication means.
4.1.4. The <status> element
The <status> element contains one or more <value> elements. It can
have multiple status values at the same time. By allowing multiple
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status values in a single <tuple> element, different types of status
values, e.g. reachability and location, can be represented by a
<tuple>. See Section 4.3 for an example with multiple status values.
4.1.5. The <value> element
The <value> element contains a CDATA value and has OPTIONAL 'type'
and 'schema' attributes. The value is case-sensitive. The 'type'
attribute indicates the type of this value which restrict the range
of the values in which the content CDATA value varies. The 'schema'
attribute is a URL pointing to the definition of the type and its
possible values, which is usually a DTD.
If the type attribute does not appear, the application MUST treat the
element as if the type is 'urn:ietf:params:cpim-presence:status-
type:basic', i.e. the 'basic' type whose possible values are either
"open" or "closed". The values "open" and "closed" has the same
meaning as OPEN and CLOSED defined in RFC 2778 respectively, and
stand for availability of receiving insatnt messages if the <tuple>
is for an instant messaging address. They also have meanings of
general availability for other communication means. But, this memo
does not specify them in detail.
When a new 'type' is defined, it MUST specify the purpose of this
type, range of values, the exact meaning of each value, and
description of possible dependencies with other types if exists.
4.1.6. The <contact> element
The <contact> element contains a URL of the contact address. It
optionally has a 'priority' attribute, whose value means a relative
priority of this contact address over the others. The value of the
attribute MUST be an integer ranged from 0 to 255 and the smaller
integer means the higher priority. If the 'priority' attribute is
omitted, applications MUST understand that the contact address has
the lowest priority. If the 'priority' value is out of the range,
applications just SHOULD ignore the value and process it as it is
omitted.
It is RECOMMENDED that applications handles a tuple with higher
priority than another one so that the priority is recognizable by
users. How to handle tuples with the same priority is up to
implementations.
4.1.7. The <note> element
The <note> element contains a CDATA value, which is usually used for
a human readable comment. A <note> element MAY appear as a child
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element of <presence> and as that of the <tuple> element. In the
former case, the comment is about the PRESENTITY and, in the latter
case, the comment is regarding the particular tuple.
4.1.8. The <timestamp> element
The <timestamp> element contains a CDATA value which is a string
indicating the date and time of the status change of this tuple. The
value of this element MUST follow the IMPP datetime format
[DateTime].
4.2. Presence Information Extensibility
The presence information extensibility framework is based on XML
namespaces [XML-NS].
4.2.1. XML Namespaces Background
All elements and some attributes are associated with a "namespace",
which is in turn associated with a globally unique URI. Any
developer can introduce their own element names, avoiding conflict by
choosing an appropriate namespace URI.
Within the presence data, element or attribute names are associated
with a particular namespace by a namespace prefix, which is a leading
part of the name, followed by a colon (":"); e.g.
<prefix:element-name ...> ... </prefix:element-name>
Where, 'prefix' is the header name prefix, 'element-name' is a name
which is scoped by the namespace associated with 'prefix'. Note that
the choice of 'prefix' is quite arbitrary; it is the corresponding
URI that defines the naming scope. Two different prefixes associated
with the same namespace URI refer to the same namespace.
A default namespace can be declared for XML elements without a
namespace prefix. The default namespace does NOT apply to attribute
names, but interpretation of an unprefixed attribute can be
determined by the containing element.
A namespace is identified by a URI. In this usage, the URI is used
simply as a globally unique identifier, and there is no requirement
that it can be used to retrieve a web resource, or for any other
purpose. Any legal globally unique URI MAY be used to identify a
namespace. (By "globally unique", we mean constructed according to
some set of rules so that it is reasonable to expect that nobody else
will use the same URI for a different purpose.)
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For further details, see the XML namespace specification [XML-NS].
4.2.2. XML Namespaces In Presence Information
A URI used as a namespace identifier in PRESENCE INFORMATION data
MUST be a full absolute-URI, per RFC 2396 [URI]. (Relative URIs and
URI- references containing fragment identifiers MUST NOT be used for
this purpose.)
The namespace URI for elements defined by this specification is a URN
[URN], using the namespace identifier 'ietf' defined by [URN-NS-IETF]
and extended by [URN-SUB-NS]:
urn:ietf:params:cpim-presence:
Thus, simple presence data might be thus:
<impp:presence xmlns:impp="urn:ietf:params:cpim-presence:">
<impp:presentity id="pres:shingo@jp.fujitsu.com">
<impp:tuple id="mobile-phone">
<impp:status>
<impp:value>open</impp:value>
</impp:status>
<impp:contact priority="9">tel:09012345678</impp:contact>
</impp:tuple>
</impp:presence>
or, using a default XML namespace:
<presence xmlns="urn:ietf:params:cpim-presence:">
<presentity id="pres:shingo@jp.fujitsu.com">
<tuple id="mobile-phone">
<status>
<value>open</value>
</status>
<contact priority="9">tel:09012345678</contact>
</tuple>
</presence>
4.2.3. Handling Of Unrecognized Element Names
Except as noted below, a processor of PRESENCE INFORMATION MUST
ignore any XML element with an unrecognized name (i.e. having an
unrecognized namespace URI, or an unrecognized local name within that
namespace). This includes all of the element content, even if it
appears to use recognized names.
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It may be that some extensions must be understood in order for the
presence information to be properly understood. In such cases, the
element name is qualified with a mustUnderstand='YES' attribute,
which attribute name is associated with the CPIM presence namespace.
NOTE: a mustUnderstand='YES' attribute within an element that is
being ignored is itself ignored. The writer of nested mandatory-
to-understand information is responsible for ensuring that any
enclosing element is also labelled with a mustUnderstand='YES'
attribute, if necessary.
This specification defines (section 4.1) elements within the
'urn:ietf:params:cpim-presence:' namespace that MUST be recognized in
CPIM presence data. Processors MUST handle these as described, even
if they do not carry a mustUnderstand attribute. The DTD (section
4.4) indicates those elements that MUST be present in a valid
presence information document.
If an agent receives PRESENCE INFORMATION containing an unrecognized
element with a mustUnderstand='YES' attribute, it should treat the
entire PRESENCE INFORMATION as unrecognized and not attempt to
process it.
4.3. Examples
4.3.1. Default Namespace And No Extensions
<presence xmlns="urn:ietf:params:cpim-presence:"
entity="pres:shingo@jp.fujitsu.com"/>
<tuple id="mobile-im">
<status>
<value>open</value>
<value
type="urn:ietf:params:cpim-presence:status-type:im">busy</value>
<value
type="urn:example-com:cpim-status-type:location"
schema="http://www.example.com/impp/location.dtd">home</value>
</status>
<contact priority="2">im:shingo@mobilecarrier.ne.jp</contact>
<note>Don't Disturb Please!</note>
<timestamp>2001-10-27T16:49:29Z</timestamp>
</tuple>
<tuple id="email">
<status>
<value>open</value>
</status>
<contact priority="1">mailto:shingo@jp.fujitsu.com</contact>
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</tuple>
<note>I'll be in Tokyo tomorrow</note>
</presence>
4.3.2. Example Presence Information Extensions
<impp:presence xmlns:impp="urn:ietf:params:cpim-presence:"
xmlns:myex="http://id.mycompany.com/cpim-presence/"
entity="pres:shingo@jp.fujitsu.com">
<myex:mytag>My extended presentity information</myex:mytag>
<impp:tuple id="mobile-phone">
<impp:status>
<impp:value>open</impp:value>
</impp:status>
<myex:mytupleelement>Extended value in tuple</myex:mytupleelement>
<impp:contact priority="9">tel:09012345678</impp:contact>
</impp:tuple>
<impp:tuple id="mobile-im">
<impp:status>
<impp:value>open</impp:value>
</impp:status>
<impp:contact priority="1">im:shingo@mobilecarrier.ne.jp</impp:contact>
</impp:tuple>
</impp:presence>
4.3.3. Example Mandatory To Understand Extensions
<impp:presence xmlns:impp="urn:iana:impp:presence:"
xmlns:myex="http://id.mycompany.com/cpim-presence/"
entity="pres:shingo@jp.fujitsu.com">
<myex:mytag>My extended presentity information</myex:mytag>
<impp:tuple id="mobile-phone">
<impp:status>
<impp:value>open</impp:value>
</impp:status>
<myex:complexExtension impp:mustUnderstand='YES'>
<myex:ex1 impp:mustUnderstand='YES'>val1</myex:ex1>
<myex:ex2>val2</myex:ex2>
</myex:mandatoryExtension>
<impp:contact priority="9">tel:09012345678</impp:contact>
</impp:tuple>
</impp:presence>
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Here, <myex:complexExtension>, <myex:ex1> must be understood, but
<myex:mytag> and <myex:ex2> may be ignored if they are not
recognized.
4.4. DTD
This section gives the Data Type Definition of the
"application/cpim-pidf+xml" format. The DTD here is presented only
for the purpose of description of the format in a well-known method.
<!ENTITY % URL "CDATA">
<!ENTITY % URI "CDATA">
<!ENTITY % TUPLEID "CDATA">
<!ENTITY % DATETIME "CDATA">
<!ENTITY % VALUETYPE "CDATA">
<!ENTITY % PRIORITY "CDATA">
<!ENTITY % NOTE "CDATA">
<!ELEMENT presence ((tuple+),note?)>
<!ATTLIST presence
xmlns %URI; "urn:ietf:params:cpim-presence:"
entity %URL; #REQUIRED
>
<!ELEMENT tuple (status,contact?,note?,timestamp?)>
<!ATTLIST tuple
id %TUPLEID; #REQUIRED
>
<!ELEMENT status (value+)>
<!ELEMENT value CDATA>
<!ATTLIST value
type %VALUETYPE;
"urn:ietf:params:cpim-presence:status-type:basic"
schema %URI; #IMPLIED
>
<!ELEMENT contact %URL;>
<!ATTLIST contact
priority %PRIORITY; #IMPLIED
>
<!ELEMENT note %NOTE;>
<!ELEMENT timestamp %DATETIME;>
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5. Wrapping 'application/cpim-pidf+xml' Data
This section profiles the use of the CPIM common message format
[CPIM-MSG] for use when conveying PRESENCE INFORMATION (per [CPIM-
MSG], section 6). Also, it describes a way to contain multiple
"application/cpim-pidf+xml" documents in a MIME multipart entity.
5.1. When Used With 'message/cpim'
In order to use the CPIM Message Format, headers needed for this
usage must be defined [CPIM-MSG]. Among the headers defined by the
CPIM message format document, the following headers MAY be used to
convey the PRESENCE INFORMATION. The default namespace and namespace
prefix implicitly defined are same as defined in the 'message/cpim'
specification document.
5.1.1. The 'From' header
The 'From' header contains the address (pres: URL) of the PRESENTITY
as the publisher of the contained PRESENCE INFORMATION. Any
application compliant to this specification MUST recognize the 'From'
header.
This use of 'From' may be considered redundant in the presence of
<presentity> element in the presence document. This header is needed
when the presence server explicitly states the publisher regardless
of the content of presence documents.
5.1.2. The 'To' header
The 'To' header contains the address (pres: URL) of the WATCHER as
the target of the NOTIFY message containing this presence document.
Any application compliant to this specification MUST recognize the
'To' header.
5.1.3. The 'DateTime' header
The 'DateTime' header contains a character string of the format
defined as IMPP datetime format [DateTime]. This value indicates the
date and time at which the content part is created. The 'DateTime'
header MUST be present as a 'message/cpim' metadata header if the
message contains an "application/cpim-pidf+xml" object. It MUST also
be recognized by any application compliant to this specification.
5.1.4. The 'NS' header
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The "NS" header is used to declare a local namespace prefix as
defined by [CPIM-MSG]. Any application compliant to this
specification MUST recognize the 'NS' header.
5.1.5. The 'Require' header
The "Require" header is used to specify a header or feature that must
be implemented by the receiver, as defined by [CPIM-MSG]. Any
application compliant to this specification MUST recognize the
'Require' header.
5.2. When Used With 'multipart/mixed'
When multiple presence documents are combined within a single
notification message, the 'multipart/mixed' content type MUST be
used. Each multipart SHOULD contain a 'Presence-Data-ID' header
defined as follows.
5.2.1. The 'Presence-Data-ID' header
The 'Presence-Data-ID' header contains the label for the unit of
update. Each labelled unit replaces any previously-received unit
that had teh same Presence-Data-ID value.
5.3. Examples
The following example is the message/cpim object containing two
presence payloads. It is supposed that the first block is published
by a PC and the second block is published by a mobile phone, and the
second block has caused the notification message conveying this
multipart content.
Content-Type: message/cpim
From: pres:shingo@jp.fujitsu.com
To: pres:suga@flab.fujitsu.co.jp
DateTime: 2001-06-01T08:35:44+09:00
Content-Type: multipart/mixed; boundary="PRESENCE-BLOCKS"
--PRESENCE-BLOCKS
Content-Type: application/cpim-pidf+xml
Presence-Data-ID: part1
<presence xmlns="urn:ietf:params:cpim-presence:">
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INTERNET DRAFT CPIM Presence Format March 2002
<presentity id="pres:shingo@jp.fujitsu.com">
<tuple id="pc-im">
<status>
<value>open</value>
<value
type="urn:ietf:params:cpim-presence:status-type:im">AWAY</value>
</status>
<contact priority="2">im:shingo@jp.fujitsu.com</contact>
<note>Boss Meeting</note>
</tuple>
<tuple id="email">
<status>
<value>open</value>
</status>
<contact priority="1">mailto:shingo@jp.fujitsu.com</contact>
</tuple>
</presence>
--PRESENCE-BLOCKS
Content-Type: application/cpim-pidf+xml
Presence-Data-ID: part2
<presence xmlns="urn:ietf:params:cpim-presence:">
<presentity id="pres:shingo@jp.fujitsu.com">
<tuple id="mobile-phone">
<status>
<value>open</value>
</status>
<contact priority="9">tel:09012345678</contact>
</tuple>
<tuple id="mobile-im">
<status>
<value>open</value>
<value
type="urn:ietf:params:cpim-presence:status-type:location"
schema="http://www.example.com/impp/location.dtd">HOME</value>
</status>
<contact priority="2">im:shingo@mobilecarrier.ne.jp</contact>
</tuple>
</presence>
--PRESENCE-BLOCKS--
6. Security Considerations
The proposed format for conveying PRESENCE INFORMATION is so designed
that it could be adaptable in circumstances under various security
requirements.
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INTERNET DRAFT CPIM Presence Format March 2002
As a typical case, a user publishing his/her PRESENCE INFORMATION may
want to sign the data to prevent from being corrupted or tampered.
This will ensure the integrity of PRESENCE INFORMATION in an end-to-
end manner. This proposal enables it by allowing MIME multipart
security framework, such as usage of the multipart/signed data type.
Another possible scenario is that of third party signing. If the
computing power of the terminal device of the publishing user is
restricted, the server side signing would be sometimes desirable to
enhance the level of security in distributing PRESENCE INFORMATION.
This enables to prevent from so-called "the man in the middle"
attacks when the presence notifications are distributed through the
proxies or gateways.
7. IANA Considerations
[[[Will need a registration template per [URN-SUB-NS], for the URN
sub-namespace 'urn:ietf:params:cpim-presence:']]]
8. References
[CPIM] D. Crocker et al., "A Common Profile for Instant Messaging
(CPIM)", draft-ietf-impp-cpim-02.txt, Work in Progress.
[CPIM-MSG] D. Atkins and G. Klyne, "Common Presence and Instant
Messaging Message Format", draft-ietf-impp-cpim-msgfmt-06.txt,
Work in Progress.
[RFC2778] M. Day, J. Rosenberg, H. Sugano, "A Model for Presence and
Instant Messaging", RFC 2778, February 2000.
[RFC2779] M. Day, S. Aggarwal, G. Mohr, and J. Vincent, "Instant
Messaging / Presence Protocol Requirements", RFC 2779, February 2000.
[RFC2119] S. Bradner, "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, BCP 14, March 1997.
[XML] T. Bray, J. Paoli, C. Sperberg-McQueen and E. Maler,
"Extensible Markup Language (XML) 1.0 (Second Edition)",
W3C Recommendation, October 2000,
<http://www.w3.org/TR/2000/REC-xml-20001006>
[MIME] Multipurpose Internet Mail Extensions. See RFC 822, RFC 2045,
RFC 2046, RFC 2047, RFC 2048, and RFC 2049.
[DateTime] G. Klyne and C.Newman, "Date and Time on the Internet:
Timestamps", draft-ietf-impp-datetime-05.txt, Work in Progress.
Sugano et al. [Page 17]
INTERNET DRAFT CPIM Presence Format March 2002
[XML-NS] Tim Bray, Dave Hollander, and Andrew Layman "Namespaces in
XML", W3C recommendation: xml-names, 14 January 1999,
<http://www.w3.org/TR/REC-xml-names>
[URI] T. Berners-Lee, R.T.Fielding and L. Masinter, "Uniform
Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998.
[URN] R. Moats, "URN Syntax", RFC 2141, May 1997.
[URN-NS-IETF] R. Moats, "A URN Namespace for IETF Documents", RFC
2648, August 1999.
[URN-SUB-NS] M. Mealling, L. Masinter, T. Hardie and G. Klyne,
"An IETF URN Sub-namespace for Registered Protocol Parameters",
Internet-Draft draft-mealling-iana-urn-01, Work in Progress.
9. Author's Addresses
Hiroyasu Sugano
Fujitsu Laboratories Ltd.
64, Nishiwaki
Ohkubo-cho
Akashi 674
Japan
E-mail: sugano.h@jp.fujitsu.com
Shingo Fujimoto
Fujitsu Laboratories Ltd.
64, Nishiwaki
Ohkubo-cho
Akashi 674
Japan
E-mail: shingo_fujimoto@jp.fujitsu.com
Graham Klyne
Baltimore Technologies - Content Security Group,
1310 Waterside,
Arlington Business Park
Theale
Reading, RG7 4SA
United Kingdom.
Telephone: +44 118 903 8000
Facsimile: +44 118 903 9000
E-mail: GK@ACM.ORG
Adrian Bateman
Sugano et al. [Page 18]
INTERNET DRAFT CPIM Presence Format March 2002
VisionTech Limited
Colton, Staffordshire, WS15 3LD
United Kingdom
E-mail: bateman@acm.org
10. Full Copyright Statement
Copyright (C) The Internet Society (2002). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Sugano et al. [Page 19]
