A Media-Based Traceroute Function for the Session Initiation Protocol (SIP)
RFC 7403
| Document | Type | RFC - Proposed Standard (November 2014; No errata) | |
|---|---|---|---|
| Author | Hadriel Kaplan | ||
| Last updated | 2015-10-14 | ||
| Stream | Internent Engineering Task Force (IETF) | ||
| Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Victor Pascual | ||
| Shepherd write-up | Show (last changed 2014-04-11) | ||
| IESG | IESG state | RFC 7403 (Proposed Standard) | |
| Action Holders |
(None)
|
||
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Richard Barnes | ||
| Send notices to | (None) | ||
| IANA | IANA review state | IANA OK - No Actions Needed | |
| IANA action state | No IANA Actions | ||
Internet Engineering Task Force (IETF) H. Kaplan
Request for Comments: 7403 Oracle
Category: Standards Track November 2014
ISSN: 2070-1721
A Media-Based Traceroute Function
for the Session Initiation Protocol (SIP)
Abstract
SIP already provides the ability to perform hop-by-hop traceroute for
SIP messages using the Max-Forwards header field to determine the
reachability path of requests to a target. A mechanism for media-
loopback calls has also been defined separately, which enables test
calls to be generated that result in media being looped back to the
originator. This document describes a means of performing hop-by-hop
traceroute-style test calls using the media-loopback mechanism to
test the media path when SIP sessions go through media-relaying back-
to-back user agents (B2BUAs).
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7403.
Kaplan Standards Track [Page 1]
RFC 7403 Media Traceroute for SIP November 2014
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
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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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. Terminology .....................................................3
3. The SIP Traceroute Mechanism ....................................4
3.1. Processing a Received Max-Forwards Header Field ............4
3.2. Answering the INVITE .......................................5
4. Security Considerations .........................................5
5. Normative References ............................................6
Acknowledgments ....................................................7
Author's Address....................................................7
1. Introduction
In many deployments, the media for SIP-created sessions does not flow
directly from the originating User Agent Client (UAC) to the
answering User Agent Server (UAS). Often, SIP B2BUAs in the SIP
signaling path also insert themselves in the media plane path by
manipulating Session Description Protocol (SDP), either for injecting
media such as rich ringtones or music-on-hold or for relaying media
in order to provide functions such as transcoding, IPv4-IPv6
conversion, NAT traversal, Secure Realtime Transport Protocol (SRTP)
termination, media steering, etc.
As more SIP domains get deployed and interconnected, the odds of a
SIP session crossing such media-plane B2BUAs increases as well as the
number of such B2BUAs any given SIP session may go through. In other
words, any given SIP session may cross any number of B2BUAs both in
the SIP signaling plane as well as the media plane.
When a failure or degradation occurs in the media plane, it is
difficult to determine where in the media path it occurred. In order
to aid managing and troubleshooting SIP-based sessions and media
Kaplan Standards Track [Page 2]
RFC 7403 Media Traceroute for SIP November 2014
traversing such B2BUAs, it would be useful to progressively test the
media path as it reaches successive B2BUAs with a test controlled
solely by the source User Agent (UA). A mechanism to perform media-
loopback test sessions has been defined in [RFC6849], but it cannot
be used directly to test B2BUAs because, typically, the B2BUAs do not
have an Address of Record (AOR) to be targeted, nor is it known a
priori which B2BUAs will be traversed for any given session.
For example, suppose calls from Alice to Bob have media problems.
Alice would like to test the media path to each B2BUA in the path to
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