1 Introduction


This document specifies the Session Initiation Protocol (SIP) Authentication Extensions protocol. This protocol extends Session Initiation Protocol (SIP) for authentication functionality. SIP is used by terminals to establish, modify, and terminate multimedia sessions or calls.

Sections 1.5, 1.8, 1.9, 2, and 3 of this specification are normative. All other sections and examples in this specification are informative.