RFC 3313 (rfc3313) - Page 2 of 16
Private Session Initiation Protocol (SIP) Extensions for Media Authorization
Alternative Format: Original Text Document
RFC 3313 SIP Extensions for Media Authorization January 2003
Table of Contents
1. Scope of Applicability......................................... 2
2. Conventions Used in this Document.............................. 3
3. Background and Motivation...................................... 3
4. Overview....................................................... 4
5. Changes to SIP to Support Media Authorization.................. 4
5.1 SIP Header Extension....................................... 5
5.2 SIP Procedures............................................. 5
5.2.1 User Agent Client (UAC)................................ 6
5.2.2 User Agent Server (UAS)................................ 6
5.2.3 Originating Proxy (OP)................................. 7
5.2.4 Destination Proxy (DP)................................. 7
6. Examples....................................................... 8
6.1 Requesting Bandwidth via RSVP Messaging.................... 8
6.1.1 User Agent Client Side................................. 8
6.1.2 User Agent Server Side................................. 10
7. Advantages of the Proposed Approach............................ 12
8. Security Considerations........................................ 13
9. IANA Considerations............................................ 13
10. Notice Regarding Intellectual Property Rights................. 13
11. Normative References.......................................... 14
12. Informative References........................................ 14
13. Contributors.................................................. 15
14. Acknowledgments............................................... 15
15. Editor's Address.............................................. 15
16. Full Copyright Statement...................................... 16
1. Scope of Applicability
This document defines a SIP extension that can be used to integrate
QoS admission control with call signaling and help guard against
denial of service attacks. The use of this extension is only
applicable in administrative domains, or among federations of
administrative domains with previously agreed-upon policies, where
both the SIP proxy authorizing the QoS, and the policy control of the
underlying network providing the QoS, belong to that administrative
domain or federation of domains. Furthermore, the mechanism is
generally incompatible with end-to-end encryption of message bodies
that describe media sessions.
This is in contrast with general Internet principles, which separate
data transport from applications. Thus, the solution described in
this document is not applicable to the Internet at large. Despite
these limitations, there are sufficiently useful specialized
deployments that meet the assumptions described above, and can accept
the limitations that result, to warrant informational publication of
this mechanism. An example deployment would be a closed network,
Marshall, Ed. Informational