SIP Standards
Core SIP Documents
RFC Document Title
RFC 2543 SIP: Session Initiation Protocol (obsolete)
RFC 3261 SIP: Session Initiation Protocol
RFC 3262 Reliability of Provisional Responses
RFC 3263 Locating SIP Servers
RFC 3264 An Offer/Answer Model with the Session Description Protocol (SDP)
RFC 3265 SIP-Specific Event Notification

SDP-Related Documents
RFC Document Title
RFC 2327 Session Description Protocol (SDP) (obsolete: see RFC 4566)
RFC 3266 Support of IPv6 in SDP
RFC 3388 Grouping Media Lines in SDP
RFC 3407 Session Description Protocol (SDP) Simple Capability Declaration
RFC 3556 SDP Bandwidth Modifiers for RTCP Bandwidth
RFC 3605 Real Time Control Protocol (RTCP) attribute in Session Description Protocol (SDP)
RFC 3890 A Transport Independent Bandwidth Modifier
RFC 4091 An Alternative NAT Semantics for SDP
RFC 4145 TCP-Based Media Transport in the SDP
RFC 4566 Session Description Protocol (SDP)
RFC 4567 Key Management Extensions for SDP and RTSP
RFC 4568 SDP Security Descriptions for Media Streams
RFC 4570 SDP Source Filters
RFC 4572 Connection-Oriented Media Transport over TLS in SDP
RFC 4574 SDP Label Attribute
RFC 4756 FEC Grouping Semantics in SDP
RFC 5027 Security Preconditions for SDP
RFC 5432 QoS Mechanism Selection in SDP
RFC 5547 SDP Offer/Answer Mechanism to Enable File Transfer
RFC 5576 Source-Specific Media Attributes in SDP

RTP-Related Documents
RFC Document Title
RFC 1889 RTP: Transport Protocol for Real-Time Applications (obsolete: see RFC 3550)
RFC 1890 RTP Profile for Audio and Video Conferences with Minimal Control (obsolete: see RFC 3551)
RFC 2198 RTP Payload for Redundant Audio Data
RFC 2733 An RTP Payload Format for Generic Forward Error Correction (obsolete: see RFC 5109)
RFC 2793 RTP Payload for Text Conversation (obsolete: see RFC 4103)
RFC 2833 RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals (obsolete: see RFC 4733)
RFC 2959 Real-Time Transport Protocol Management Information Base
RFC 3389 RTP Payload for Comfort Noise
RFC 3611 RTP Control Protocol Extended Reports (RTCP XR)
RFC 3711 The Secure Real-time Transport Protocol (SRTP)
RFC 4103 RTP Payload for Text Conversation
RFC 4571 Framing RTP and RTCP Packets over Connection-Oriented Transport
RFC 4585 Extended RTP Profile for RTCP-Based Feedback (RTP/AVPF)
RFC 4586 RTP/AVPF: Results of the Timing Rule Simulations
RFC 4588 RTP Retransmission Payload Format
RFC 4771 Integrity Transform Carrying Roll-Over for SRTP
RFC 4733 RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals
RFC 4961 Symmetric RTP / RTP Control Protocol
RFC 3550 RTP: Transport Protocol for Real-Time Applications
RFC 3551 RTP Profile for Audio and Video Conferences with Minimal Control
RFC 5109 RTP Payload Format for Generic Forward Error Correction
RFC 5117 RTP Topologies
RFC 5450 Transmission Time Offsets in RTP Streams
RFC 5506 Support for Reduced-Size RTCP: Opportunities and Consequences

HTTP-Related Documents
RFC Document Title
RFC 2616 Hypertext Transfer Protocol -- HTTP/1.1
RFC 2617 HTTP Authentication: Basic and Digest Access Authentication
RFC 3310 HTTP Digest Authentication Using Authentication and Key Agreement (AKA)

MIME-Related Documents
RFC Document Title
RFC 1847 Security Multiparts for MIME: Multipart/Signed and Multipart/Encrypted
RFC 2045 MIME Part One: Format of Internet Message Bodies
RFC 2046 MIME Part Two: Media Types
RFC 2047 MIME Part Three: Message Header Extensions for Non-ASCII Text
RFC 2048 MIME Part Four: Registration Procedures (obsolete: see RFC 4288 and RFC 4289)
RFC 2633 S/MIME Version 3 Message Specification
RFC 3204 MIME media types for ISUP and QSIG Objects
RFC 3420 Internet Media Type message/sipfrag
RFC 3555 MIME Type Registration of RTP Payload Formats
RFC 4288 Media Type Specifications and Registration Procedures
RFC 4289 Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures

SIP Standards Track Documents (Options, Extensions, etc.)
RFC Document Title
RFC 2976 The SIP INFO Method
RFC 2848 Extensions for IP Access to Telephone Call Services
RFC 3050 CGI for SIP
RFC 3311 UPDATE Method
RFC 3312 Integration of Resource Management and SIP
RFC 3313 Private SIP Extensions for Media Authorization
RFC 3319 DHCPv6 Options for SIP Servers
RFC 3323 A Privacy Mechanism for SIP
RFC 3324 Short Term Requirements for Network Asserted Identity
RFC 3325 Private Extensions to SIP for Asserted Identity within Trusted Networks
RFC 3326 The Reason Header Field
RFC 3327 Extension Header Field for Registering Non-Adjacent Contacts
RFC 3329 Security Mechanism Agreement
RFC 3361 DHCP-for-IPv4 Option for SIP Servers
RFC 3372 SIP for Telephones (SIP-T): Context and Architectures
RFC 3398 ISUP to SIP Mapping
RFC 3428 SIP Extension for Instant Messaging
RFC 3455 Private Header Extensions for 3GPP
RFC 3515 The Session Initiation Protocol (SIP) Refer Method
RFC 3578 Mapping ISUP Overlapped Signalling to SIP
RFC 3581 Extension to SIP for Symmetric Response Routing
RFC 3608 Extension Header Field for Service Route Discovery During Registration
RFC 3680 SIP Event Package for Registrations
RFC 3840 Indicating User Agent Capabilities in SIP
RFC 3841 Caller Preferences for SIP
RFC 3842 Message Summary and Message Waiting Indication Event Package
RFC 3856 Presence Event Package
RFC 3857 A Watcher Information Event Template-Package
RFC 3891 "Replaces" Header
RFC 3892 Referred-By Mechanism
RFC 3893 SIP Authenticated Identity Body (AIB)
RFC 3911 SIP "Join" Header
RFC 3903 Event State Publication
RFC 3959 Early Session Disposition Type
RFC 3960 Early Media and Ringing Tone Generation
RFC 4028 Session Timers in the Session Initiation Protocol (SIP)
RFC 4235 An INVITE-Initiated Dialog Event Package for SIP
RFC 4244 Extension for Request History Information
RFC 4320 Actions Addressing Identified Issues with the SIP Non-INVITE Transaction
RFC 4411 Extending the SIP Reason Header for Preemption Events
RFC 4412 Communications Resource Priority for SIP
RFC 4474 Enhancements for Authenticated Identity Management in SIP
RFC 4483 A Mechanism for Content Indirection in SIP
RFC 4488 Suppression of SIP REFER Method Implicit Subscription
RFC 4575 SIP Event Package for Conference State
RFC 4662 SIP Event Notification Extension for Resource Lists
RFC 4730 Event Package for KPML
RFC 4780 MIB for SIP
RFC 4904 Representing Trunk Groups in tel/sip URIs
RFC 4916 Connected Identity in SIP
RFC 4967 Dial String Parameter for the SIP URI
RFC 4975 Message Session Relay Protocol (MSRP)
RFC 4976 Relay Extension for MSRP
RFC 5079 Rejecting Anonymous Requests in SIP
RFC 5196 SIP User Agent Capability Extension to Presence Information Data Format (PIDF)
RFC 5263 SIP Extension for Partial Notification of Presence Information
RFC 5264 Publication of Partial Presence Information
RFC 5373 Requesting Answering Modes for SIP
RFC 5478 IANA Registration of new SIP Resource-Priority Namespaces
RFC 5509 IANA Registration Instant Messaging and Presence DNS SRV RRs for SIP
RFC 5552 SIP Interface to VoiceXML Media Services
RFC 5589 SIP Call Control - Transfer
RFC 5627 Obtaining and Using Globally Routable User Agent URIs (GRUUs) in SIP
RFC 5628 Registration Event Package Extension for SIP GRUUs
RFC 5629 A Framework for Application Interaction in SIP
RFC 5630 The Use of the SIPS URI Scheme in SIP
RFC 5631 SIP Session Mobility
RFC 5658 Addressing Record-Route Issues in SIP

SIP Informational RFCs and BCP Documents
RFC Document Title
RFC 3087 Control of Service Context using SIP Request-URI
RFC 3351 User Requirements for SIP in Support of Speech/Hearing Impaired
RFC 3603 Private SIP Proxy-to-Proxy Extensions for PacketCable Distributed Call Signaling
RFC 3665 SIP Basic Call Flow Examples
RFC 3702 Authentication, Authorization, and Accounting Requirements for SIP
RFC 3824 Using E.164 numbers with SIP
RFC 3968 IANA Registry for SIP Header Field
RFC 3969 IANA Registry for SIP URI
RFC 3976 Interworking SIP and IN Applications
RFC 4117 Transcoding Services Invocation using 3PCC
RFC 4123 SIP-H.323 Interworking Requirements
RFC 4168 SCTP as a transport for SIP
RFC 4189 Requirements for End-to-Middle Security for SIP
RFC 4240 Basic Network Media Services with SIP
RFC 4245 High-Level Requirements for Tightly Coupled SIP Conferencing
RFC 4317 SDP Offer/Answer Examples
RFC 4321 Problems Identified Associated with the SIP Non-INVITE Transaction
RFC 4353 A Framework for Conferencing with SIP
RFC 4354 SIP Event Package and Data Format for Push-to-Talk over Cellular (PoC) Service
RFC 4453 Requirements for Consent-Based Communications in the SIP
RFC 4457 SIP P-User-Database Private-Header (P-Header)
RFC 4458 SIP URIs for Applications such as Voicemail and Interactive Voice Response (IVR)
RFC 4475 SIP Torture Test Messages
RFC 4484 Trait-Based Authorization Requirements for SIP
RFC 4504 SIP Telephony Device Requirements and Configuration
RFC 4538 Request Authorization through Dialog Identification in SIP
RFC 4596 Guidelines for Usage of the SIP Caller Preferences Extension
RFC 4579 SIP Call Control - Conferencing for User Agents
RFC 4964 The P-Answer-State Header Extension to SIP
RFC 5002 SIP P-Profile-Key Private Header (P-Header)
RFC 5009 Private Header (P-Header) Extension to SIP for Authorization of Early Media
RFC 5039 SIP and Spam
RFC 5057 Multiple Dialog Usages in SIP
RFC 5118 SIP Torture Test Messages for IPv6
RFC 5194 Framework for Real-Time Text using SIP
RFC 5411 A Hitchhiker's Guide to SIP
RFC 5479 Requirements and Analysis of Media Security Management Protocols
RFC 5502 SIP P-Served-User Private-Header (P-Header) for the 3GPP Core Network

SIP-Related Documents
RFC Document Title
RFC 3219 Telephony Routing over IP (TRIP) (tutorial)
RFC 3320 Signalling Compression
RFC 3321 Signalling Compression - Extended Operations
RFC 3322 Signalling Compression - Requirements and Assumptions
RFC 3486 Compressing the Session Initiation Protocol (SIP)
RFC 3485 SIP and SDP Static Dictionary for Signaling Compression
RFC 5503 Private SIP Proxy-to-Proxy Extensions for Supporting the PacketCable Distributed Call Signaling Architecture (obsolete, see RFC 5503)
RFC 3725 Best Current Practices for 3PCC in SIP
RFC 3764 enumservice registration for SIP Addresses-of-Record
RFC 4077 A Negative Acknowledgement Mechanism for Signaling Compression
RFC 4083 3GPP Release 5 Requirements on SIP
RFC 4092 Using SDP Alternative NAT Semantics in SIP
RFC 4465 Signaling Compression (SigComp) Torture Tests
RFC 4497 Interworking between the SIP and QSIG
RFC 4740 Diameter SIP Application
RFC 5049 Applying Signaling Compression to SIP
RFC 5112 The Presence-Specific Static Dictionary for Signaling Compression
RFC 5115 TRIP attribute for Resource Priority
RFC 5503 Private SIP Proxy-to-Proxy Extensions for Supporting the PacketCable Distributed Call Signaling Architecture

Directory Services Documents
Standard Document Title
H.350 Directory Services Architecture for Multimedia Conferencing
H.350.4 Directory Services Architecture for SIP