RFC 4235 - An INVITE-Initiated Dialog Event Package for the Session Initiation Protocol (SIP)
RFC 3325 - Private Extensions to the Session Initiation Protocol (SIP) for Asserted Identity within Trusted Networks
FC 2387 - RThe MIME Multipart/Related Content-type
RFC 2976 - The SIP INFO Method
RFC 3262 - Reliability of Provisional Responses in the Session Initiation Protocol (SIP)
RFC 3263 - Session Initiation Protocol (SIP): Locating SIP Servers
RFC 3264 - An Offer/Answer Model with the Session Description Protocol (SDP)
RFC 3265 - Session Initiation Protocol (SIP)-Specific Event Notification
RFC 3311 - The Session Initiation Protocol (SIP) UPDATE Method
RFC 3325 - Private Extensions to the Session Initiation Protocol (SIP) for Asserted Identity within Trusted Networks
RFC 3515 - The Session Initiation Protocol (SIP) Refer Method
RFC 3555 - MIME Type Registration of RTP Payload Formats
RFC 3611 - RTP Control Protocol Extended Reports (RTCP XR)
RFC 3665 - Session Initiation Protocol (SIP) Basic Call Flow Examples
RFC 3725 - Best Current Practices for Third Party Call Control (3pcc) in the Session Initiation Protocol (SIP)
RFC 3842 - A Message Summary and Message Waiting Indication Event Package for the Session Initiation Protocol (SIP)
RFC 3856 - A Presence Event Package for the Session Initiation Protocol (SIP)
RFC 3891 - The Session Initiation Protocol (SIP) "Replaces" Header
RFC 3892 - The Session Initiation Protocol (SIP) Referred-By Mechanism
RFC 3959 - The Early Session Disposition Type for the Session Initiation Protocol (SIP)
RFC 3960 - Early Media and Ringing Tone Generation in the Session Initiation Protocol (SIP)
RFC 3968 - The Internet Assigned Number Authority (IANA) Header Field Parameter Registry for the Session Initiation Protocol (SIP)