Managing Client-Initiated Connections in the Session Initiation Protocol
RFC 5626, “Managing Client-Initiated Connections in the Session Initiation Protocol”, is a Proposed Standard document published in October 2009 by C. Jennings, R. Mahy, F. Audet. It updates RFC 3261, RFC 3327. The canonical text is published by the RFC Editor.
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. [STANDARDS-TRACK]
What “Proposed Standard” means
An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.
The canonical text of RFC 5626 is hosted at rfc-editor.org. Available in TXT,HTML.
- RFC 5625 DNS Proxy Implementation Guidelines
- RFC 5627 Obtaining and Using Globally Routable User Agent URIs in the Session Initiation Protocol
- RFC 5624 Quality of Service Parameters for Usage with Diameter
- RFC 5628 Registration Event Package Extension for Session Initiation Protocol Globally Routable User Agent URIs
- RFC 5623 Framework for PCE-Based Inter-Layer MPLS and GMPLS Traffic Engineering
- RFC 5629 A Framework for Application Interaction in the Session Initiation Protocol
- RFC 5622 Profile for Datagram Congestion Control Protocol Congestion ID 4: TCP-Friendly Rate Control for Small Packets
- RFC 5630 The Use of the SIPS URI Scheme in the Session Initiation Protocol