Requirements for Marking SIP Messages to be Logged
draft-ietf-insipid-logme-reqs-02
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 8123.
|
|
|---|---|---|---|
| Author | Peter Dawes | ||
| Last updated | 2015-01-28 (Latest revision 2015-01-21) | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Reviews |
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by Stewart Bryant
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| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | Gonzalo Salgueiro | ||
| IESG | IESG state | Became RFC 8123 (Informational) | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | "Gonzalo Salgueiro" <gsalguei@cisco.com> |
draft-ietf-insipid-logme-reqs-02
Internet Engineering Task Force P. Dawes
Internet-Draft Vodafone Group
Intended status: Informational January 21, 2015
Expires: July 25, 2015
Requirements for Marking SIP Messages to be Logged
draft-ietf-insipid-logme-reqs-02
Abstract
SIP networks use signalling monitoring tools to diagnose user
reported problem and for regression testing if network or client
software is upgraded. As networks grow and become interconnected,
including connection via transit networks, it becomes impractical to
predict the path that SIP signalling will take between clients, and
therefore impractical to monitor SIP signalling end-to-end.
This draft describes requirements for adding an indicator to the SIP
protocol which can be used to mark signalling as of interest to
logging. Such marking will typically be applied as part of network
testing controlled by the network operator and not used in regular
client signalling. However, such marking can be carried end-to-end
including the SIP terminals, even if a session originates and
terminates in different networks.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on July 25, 2015.
Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in this Document . . . . . . . . . . . . . . 2
3. Motivating Scenario . . . . . . . . . . . . . . . . . . . . . 3
4. Basic Diagnostic Procedure . . . . . . . . . . . . . . . . . 4
5. Requirements for a "Log Me" Marker . . . . . . . . . . . . . 5
6. Security Considerations . . . . . . . . . . . . . . . . . . . 6
6.1. Trust Domain . . . . . . . . . . . . . . . . . . . . . . 6
6.2. Security Threats . . . . . . . . . . . . . . . . . . . . 6
6.2.1. "Log Me" Marking . . . . . . . . . . . . . . . . . . 6
6.2.2. Sending Logged Information . . . . . . . . . . . . . 7
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . 7
8.2. Informative References . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
If users experience problems with setting up sessions using SIP,
their service provider needs to find out why by examining the SIP
signalling. Also, if network or client software or hardware is
upgraded regression testing is needed. Such diagnostics apply to a
small proportion of network traffic and can apply end-to-end, even if
signalling crosses several networks possibly belonging to several
different network operators. It may not be possible to predict the
path through those networks in advance, therefore a mechanism is
needed to mark a session as being of interest to enable SIP entities
along the signalling path to provide diagnostic logging. This draft
describes the requirements for such a "log me" marker for SIP
signalling.
2. Conventions Used in this Document
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 [RFC2119].
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3. Motivating Scenario
Signalling for SIP session setup can cross several networks, and
these networks may not have common ownership and also may be in
differrent countries. If a single operator wishes to perform
regression testing or fault diagnosis end-to-end, the separate
ownership of networks that carry the signalling and the explosion in
the number of possible signalling paths through SIP entities from the
originating to the terminating user make it impractical to pre-
configure logging of an end-to-end SIP signalling of a session of
interest.
The figure below shows an example of a signalling path through
multiple networks.
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+------------------+ +------------------+
| COUNTRY A | | COUNTRY B |
| Operator A | | Operator A |
| | | |
| SIP Phones | | SIP Phones |
| | //| |
+------------------+ // +------------------+
| //
| //
,'```', // +------------------+
.`',.' `..'``',<==// | COUNTRY B |
,' Operator A `', | Operator A |
; Backbone Network ..'--| |
', ,., .'` | PSTN phones |
'.,.`'.,,,.` `''` | |
|| +------------------+
||
\/
+------------------+
| |
| Transit Network |
| |
| |\\
+------------------+ \\
| \\
| \\
+------------------+ \\ +------------------+
| COUNTRY D | \\ | COUNTRY C |
| Operator C | \\=>| Operator B |
| | | |
| SIP Phones | | SIP Phones |
| | | |
+------------------+ +------------------+
Figure 1: Example signalling path through multiple networks
4. Basic Diagnostic Procedure
The skeleton diagnostic procedure is as follows:
o The user's terminal is placed in debug mode. The terminal logs
its own signalling and inserts a "log me" marker into SIP requests
for session setup
o All SIP entities that the signalling traverses, from the first
proxy the terminal connects to at the edge of the network to the
destination client terminal, can detect that the "log me" marker
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is present and can log SIP requests and responses that contain the
marker if configured to do so.
o Subsequent responses and requests in the same dialog are logged.
o Logging stops, either because the dialog has ended or because a
'stop event', typically expiry of a certain amount of time,
occurred
o The user's terminal and any other SIP entity that has logged
signalling sends logs to a server that is co-ordinating
diagnostics.
5. Requirements for a "Log Me" Marker
o REQ1: It MUST be possible to mark a SIP request or response as of
interest for logging by inserting a "log me" marker. This is
known as "log me" marking.
o REQ2: It MUST be possible for a "log me" marker to cross network
boundaries.
o REQ3: A "log me" marker is most effective if it passes end-to-end.
However, source networks should behave responsibly and not leave
it to a downstream network to detect and remove a marker that it
will not use. A "log me" marker SHOULD be removed at trust domain
boundaries.
o REQ4: SIP entities SHOULD log SIP requests or responses with a
"log me" marker.
o REQ5: If a UA receives a request with a "log me" marker, it MUST
echo that "log me" marker in responses to that request.
o REQ6: A SIP proxy MAY perform "log me" marking of requests and
responses. Typical cases where a proxy needs to perform "log me"
marking are when a UA has not marked a request and when responses
received on a dialog of interest for logging do not contain a "log
me" marker. In these cases, the entity that performs "log me"
marking is stateful inasmuch as it must remember when a dialog is
of interest for logging.
o REQ7: For SIP proxies, logging of SIP requests that contain a "log
me" marker MAY be stateless. For example, it is OPTIONAL for a
SIP entity to maintain state of which SIP requests contained a
"log me" marker in order to log responses to those requests.
Echoing a "log me" marker in responses is the responsibility of
the UA that receives a request.
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o REQ8: A "log me" marker MAY include an identifier that indicates
the test case that caused it to be inserted, known as a test case
identifier. The test case identifier does not have any impact on
session setup, it is used by the diagnostic server to collate all
logged SIP requests and responses to the initial SIP request in a
dialog or standalone transaction. The Session-ID described in RFC
7206 [RFC7206] and I-D.ietf-insipid-session-id-12
[I-D.ietf-insipid-session-id] could be used as the test case
identifier but it would be useful for the UA to log a human
readable name together with this Session-ID when it performs "log
me" marking of an initial SIP request.
6. Security Considerations
Potential security impacts of a "log me" marker are whether the
marker itself contains any sensitive information, whether detecting
its presence or absence reveals sensitive information, and whether
maliciously adding a "log me" can be used to attack a network. This
section analyses these potential impacts.
6.1. Trust Domain
Since a "log me" marker may cause a SIP entity to log the SIP header
and body of a request or response, the "log me" marker should be
removed at a trust domain boundary. If a prior agreement to log
sessions exists with the net hop network then the "log me" marker
might not be removed.
6.2. Security Threats
6.2.1. "Log Me" Marking
The "log me" marker is not sensitive information, although it will
sometimes be inserted because a particular device is experiencing
problems.
The presence of a "log me" marker will cause some SIP entities to log
signalling. Therefore, this marker must be removed at the earliest
opportunity if it has been incorrectly inserted.
Activating a debug mode affects the operation of a terminal,
therefore it must be supplied by an authorized server to an
authorized terminal, it must not be altered in transit, and it must
not be readable by an unauthorized third party.
Logged signalling is privacy-sensitive data, therefore it must be
passed to an authorized server, it must not be altered in transit,
and it must not be readable by an unauthorized third party.
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6.2.2. Sending Logged Information
A SIP entity that has logged information should encrypt it, such that
it can be decrypted only by the debug server, before sending it to a
debug server in order to protect the content of logs from a third
party.
7. Acknowledgments
The author wishes to thank Paul Kyzivat, Christer Holmberg, James
Polk, Hadriel Kaplan, Keith Drage, and Gonzalo Salgueiro for their
constructive comments and guidance while developing this document.
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
8.2. Informative References
[I-D.ietf-insipid-session-id]
Jones, P., Polk, J., Salgueiro, G., and C. Pearce, "End-
to-End Session Identification in IP-Based Multimedia
Communication Networks", draft-ietf-insipid-session-id-12
(work in progress), January 2015.
[RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
June 1999.
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261,
June 2002.
[RFC3311] Rosenberg, J., "The Session Initiation Protocol (SIP)
UPDATE Method", RFC 3311, October 2002.
[RFC3428] Campbell, B., Rosenberg, J., Schulzrinne, H., Huitema, C.,
and D. Gurle, "Session Initiation Protocol (SIP) Extension
for Instant Messaging", RFC 3428, December 2002.
[RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC
Text on Security Considerations", BCP 72, RFC 3552, July
2003.
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[RFC3903] Niemi, A., "Session Initiation Protocol (SIP) Extension
for Event State Publication", RFC 3903, October 2004.
[RFC6086] Holmberg, C., Burger, E., and H. Kaplan, "Session
Initiation Protocol (SIP) INFO Method and Package
Framework", RFC 6086, January 2011.
[RFC7206] Jones, P., Salgueiro, G., Polk, J., Liess, L., and H.
Kaplan, "Requirements for an End-to-End Session
Identification in IP-Based Multimedia Communication
Networks", RFC 7206, May 2014.
Author's Address
Peter Dawes
Vodafone Group
The Connection
Newbury, Berkshire RG14 2FN
UK
Email: peter.dawes@vodafone.com
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