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 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. 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 toShow full document text