Internet DRAFT - draft-dawes-insipid-logme-reqs
draft-dawes-insipid-logme-reqs
Internet Engineering Task Force P. Dawes
Internet-Draft Vodafone Group
Intended status: Standards Track January 16, 2014
Expires: July 20, 2014
Requirements for Marking SIP Messages to be Logged
draft-dawes-insipid-logme-reqs-00
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
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
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 20, 2014.
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
Dawes Expires July 20, 2014 [Page 1]
Internet-Draft log me marker January 2014
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
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2
3. Motivating Scenario . . . . . . . . . . . . . . . . . . . . . 3
4. Skeleton 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. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
7.1. Normative References . . . . . . . . . . . . . . . . . . 7
7.2. Informative References . . . . . . . . . . . . . . . . . 7
Appendix A. Additional Stuff . . . . . . . . . . . . . . . . . . 8
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. Requirements Language
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].
Dawes Expires July 20, 2014 [Page 2]
Internet-Draft log me marker January 2014
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.
Dawes Expires July 20, 2014 [Page 3]
Internet-Draft log me marker January 2014
+------------------+ +------------------+
| 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. Skeleton 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 is
Dawes Expires July 20, 2014 [Page 4]
Internet-Draft log me marker January 2014
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 shall 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 shall 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 shall
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 not required 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.
Dawes Expires July 20, 2014 [Page 5]
Internet-Draft log me marker January 2014
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 I-D
.ietf-insipid-session-id-reqts [I-D.ietf-insipid-session-id-reqts]
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
All drafts are required to have a security considerations section.
See RFC 3552 [RFC3552] for a guide.
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.
Dawes Expires July 20, 2014 [Page 6]
Internet-Draft log me marker January 2014
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. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
7.2. Informative References
[I-D.ietf-insipid-session-id-reqts]
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", draft-ietf-insipid-session-id-reqts-07 (work in
progress), June 2013.
[RFC2234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 2234, November 1997.
[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.
[RFC3903] Niemi, A., "Session Initiation Protocol (SIP) Extension
for Event State Publication", RFC 3903, October 2004.
Dawes Expires July 20, 2014 [Page 7]
Internet-Draft log me marker January 2014
[RFC6086] Holmberg, C., Burger, E., and H. Kaplan, "Session
Initiation Protocol (SIP) INFO Method and Package
Framework", RFC 6086, January 2011.
Appendix A. Additional Stuff
This becomes an Appendix.
Author's Address
Peter Dawes
Vodafone Group
The Connection
Newbury, Berkshire RG14 2FN
UK
Phone: +44 7717 275009
Email: peter.dawes@vodafone.com
