Managing Client-Initiated Connections in the Session Initiation Protocol (SIP)
RFC 5626
|
| Document |
Type |
|
RFC - Proposed Standard
(October 2009; No errata)
|
|
Last updated |
|
2015-10-14
|
|
Replaces |
|
draft-jennings-sipping-outbound
|
|
Stream |
|
IETF
|
|
Formats |
|
plain text
pdf
html
bibtex
|
|
Reviews |
|
|
| Stream |
WG state
|
|
(None)
|
|
Document shepherd |
|
No shepherd assigned
|
| IESG |
IESG state |
|
RFC 5626 (Proposed Standard)
|
|
Consensus Boilerplate |
|
Unknown
|
|
Telechat date |
|
|
|
Responsible AD |
|
Robert Sparks
|
|
Send notices to |
|
audet@nortel.com
|
Network Working Group C. Jennings, Ed.
Request for Comments: 5626 Cisco Systems
Updates: 3261, 3327 R. Mahy, Ed.
Category: Standards Track Unaffiliated
F. Audet, Ed.
Skype Labs
October 2009
Managing Client-Initiated Connections
in the Session Initiation Protocol (SIP)
Abstract
The Session Initiation Protocol (SIP) allows proxy servers to
initiate TCP connections or to send asynchronous UDP datagrams to
User Agents in order to deliver requests. However, in a large number
of real deployments, many practical considerations, such as the
existence of firewalls and Network Address Translators (NATs) or the
use of TLS with server-provided certificates, prevent servers from
connecting to User Agents in this way. This specification defines
behaviors for User Agents, registrars, and proxy servers that allow
requests to be delivered on existing connections established by the
User Agent. It also defines keep-alive behaviors needed to keep NAT
bindings open and specifies the usage of multiple connections from
the User Agent to its registrar.
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (c) 2009 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
Jennings, et al. Standards Track [Page 1]
RFC 5626 Client-Initiated Connections in SIP October 2009
the Trust Legal Provisions and are provided without warranty as
described in the BSD License.
This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November
10, 2008. The person(s) controlling the copyright in some of this
material may not have granted the IETF Trust the right to allow
modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other
than English.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 5
2.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 5
3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. Summary of Mechanism . . . . . . . . . . . . . . . . . . . 6
3.2. Single Registrar and UA . . . . . . . . . . . . . . . . . 7
3.3. Multiple Connections from a User Agent . . . . . . . . . . 8
3.4. Edge Proxies . . . . . . . . . . . . . . . . . . . . . . . 10
3.5. Keep-Alive Technique . . . . . . . . . . . . . . . . . . . 11
3.5.1. CRLF Keep-Alive Technique . . . . . . . . . . . . . . 12
3.5.2. STUN Keep-Alive Technique . . . . . . . . . . . . . . 12
4. User Agent Procedures . . . . . . . . . . . . . . . . . . . . 13
4.1. Instance ID Creation . . . . . . . . . . . . . . . . . . . 13
4.2. Registrations . . . . . . . . . . . . . . . . . . . . . . 14
4.2.1. Initial Registrations . . . . . . . . . . . . . . . . 14
4.2.2. Subsequent REGISTER Requests . . . . . . . . . . . . . 16
4.2.3. Third-Party Registrations . . . . . . . . . . . . . . 17
4.3. Sending Non-REGISTER Requests . . . . . . . . . . . . . . 17
4.4. Keep-Alives and Detecting Flow Failure . . . . . . . . . . 18
4.4.1. Keep-Alive with CRLF . . . . . . . . . . . . . . . . . 19
Show full document text