STRAW Working Group H. Kaplan
Internet Draft Oracle
Intended status: Standards Track July 10, 2014
Expires: January 10, 2015
A Media-based Traceroute Function for
the Session Initiation Protocol (SIP)
draft-ietf-straw-sip-traceroute-03
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 B2BUAs.
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with
the provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
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."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on January 10, 2015.
Kaplan Expires January 2015 [Page 1]
Internet-Draft Media-Traceroute for SIP July 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
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. 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. IANA Considerations.........................................6
6. Acknowledgments.............................................6
7. References..................................................6
7.1. Normative References...................................6
Author's Address..................................................7
1. Introduction
In many deployments, the media for SIP-created sessions does not
flow directly from the originating user's UAC to the answering
user's UAS. Often, SIP B2BUAs in the SIP signaling path also insert
themselves in the media plane path by manipulating 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, 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 B2BUA's
both in the SIP signaling plane as well as media plane.
When a failure or degradation occurs in the media plane, it is
difficult to determine where in the media path they occurred. In
Kaplan Expires - January 2015 [Page 2]
Internet-Draft Media-Traceroute for SIP July 2014
order to aid managing and troubleshooting SIP-based sessions and
datatracker.ietf.org