Internet Assigned Numbers Authority Session Description Protocol (SDP) Parameters Created 2001-06-15 Last Updated 2023-06-06 Available Formats [IMG] XML [IMG] HTML [IMG] Plain text Registries included below • media • proto • bwtype • nettype • addrtype • enckey • attribute-name (formerly "att-field") • content SDP Parameters • Semantics for the "group" SDP Attribute • "rtcp-fb" Attribute Values • "ack" and "nack" Attribute Values • "depend" SDP Attribute Values • "cs-correlation" Attribute Values • Semantics for the "ssrc-group" SDP Attribute • SDP/RTSP key management protocol identifiers • Codec Control Messages • QoS Mechanism Tokens • SDP Capability Negotiation Option Tags • SDP Capability Negotiation Configuration Parameters Registry • Timestamp Reference Clock Source Parameters • Media Clock Source Parameters • Multiplexing Categories • association-usage Name Registry • RID Attribute Parameters • Candidate Attribute Extensions media Registration Procedure(s) Standards Action Reference [RFC8866] Available Formats [IMG] CSV Type SDP Name Reference media audio [RFC8866] media video [RFC8866] media text [RFC8866] media application [RFC8866] media message [RFC8866] media image [RFC6466] proto Registration Procedure(s) RFC Required Reference [RFC8866] Note Standards Track RFC preferred. Available Formats [IMG] CSV Type SDP Name Reference proto RTP/AVP [RFC8866] proto udp [RFC8866] proto vat [1] proto rtp [1] proto udptl [ITU-T Recommendation T.38, 'Procedures for real-time Group 3 facsimile communication over IP networks', June 1998. (Section 9)] proto TCP [RFC4145] proto RTP/AVPF [RFC4585] proto TCP/RTP/AVP [RFC4571] proto RTP/SAVP [RFC3711] proto TCP/BFCP [RFC8856] proto TCP/TLS/BFCP [RFC8856] proto TCP/TLS [RFC8122] proto FLUTE/UDP [RFC-mehta-rmt-flute-sdp-05] proto TCP/MSRP [RFC4975] proto TCP/TLS/MSRP [RFC4975] proto DCCP [RFC5762] proto DCCP/RTP/AVP [RFC5762] proto DCCP/RTP/SAVP [RFC5762] proto DCCP/RTP/AVPF [RFC5762] proto DCCP/RTP/SAVPF [RFC5762] proto RTP/SAVPF [RFC5124] proto UDP/TLS/RTP/SAVP [RFC5764] proto DCCP/TLS/RTP/SAVP [RFC5764] proto UDP/TLS/RTP/SAVPF [RFC5764] proto DCCP/TLS/RTP/SAVPF [RFC5764] proto UDP/MBMS-FEC/RTP/AVP [RFC6064] proto UDP/MBMS-FEC/RTP/SAVP [RFC6064] proto UDP/MBMS-REPAIR [RFC6064] proto FEC/UDP [RFC6364] proto UDP/FEC [RFC6364] proto TCP/MRCPv2 [RFC6787] proto TCP/TLS/MRCPv2 [RFC6787] proto PSTN [RFC7195] proto UDP/TLS/UDPTL [RFC7345] proto voice [RFC2848] proto fax [RFC2848] proto pager [RFC2848] proto TCP/RTP/AVPF [RFC7850] proto TCP/RTP/SAVP [RFC7850] proto TCP/RTP/SAVPF [RFC7850] proto TCP/DTLS/RTP/SAVP [RFC7850] proto TCP/DTLS/RTP/SAVPF [RFC7850] proto TCP/TLS/RTP/AVP [RFC7850] proto TCP/TLS/RTP/AVPF [RFC7850] proto TCP/WS/BFCP [RFC8857] proto TCP/WSS/BFCP [RFC8857] proto UDP/DTLS/SCTP [RFC8841] proto TCP/DTLS/SCTP [RFC8841] proto TCP/DTLS/BFCP [RFC8856] proto UDP/BFCP [RFC8856] proto UDP/TLS/BFCP [RFC8856] bwtype Registration Procedure(s) Standards Action Reference [RFC8866][RFC8859] Available Formats [IMG] CSV Type SDP Name Mux Category Reference bwtype CT NORMAL [RFC8866][RFC8859] bwtype AS SUM [RFC8866][RFC8859] bwtype RS SUM [RFC3556][RFC8859] bwtype RR SUM [RFC3556][RFC8859] bwtype TIAS SPECIAL [RFC3890][RFC8859] nettype Registration Procedure(s) RFC Required Reference [RFC8866] Available Formats [IMG] CSV Type SDP Name Usable addrtype Values Reference nettype IN IP4, IP6 [RFC8866] nettype TN RFC2543 [RFC2848] nettype ATM NSAP, GWID, E164 [RFC3108] nettype PSTN E164 [RFC7195] addrtype Registration Procedure(s) RFC Required Reference [RFC8866] Available Formats [IMG] CSV Type SDP Name Reference addrtype IP4 [RFC8866] addrtype IP6 [RFC8866] addrtype NSAP [RFC3108] addrtype GWID [RFC3108] addrtype E164 [RFC7195][RFC3108] enckey Registration Procedure(s) REGISTRY OBSOLETED - No further registrations accepted Reference [RFC8866] Available Formats [IMG] CSV Type SDP Name Reference enckey clear [RFC8866] enckey base64 [RFC8866] enckey uri [RFC8866] enckey prompt [RFC8866] attribute-name (formerly "att-field") Registration Procedure(s) Specification Required Expert(s) Flemming Andreasen Reference [RFC8866][RFC8864][RFC8859] Available Formats [IMG] CSV Type SDP Name Usage Mux Category Reference Level attribute 3ge2ae media IDENTICAL [3GPP TS 24.229 12.14.0][Frederic_Firmin] attribute 3gpp_MaxRecvSDUSize session, NORMAL [3GPP TS 26.114 v16.3.0][_3GPP_Specifications_Manager] media attribute 3gpp_mtsi_app_adapt media IDENTICAL-PER-PT [3GPP TS 26.114 v16.3.0][Ozgur_Oyman] attribute 3gpp_sync_info session, NORMAL [3GPP TS 26.114 v16.3.0][_3GPP_Specifications_Manager] media attribute 3GPP-Adaptation-Support media CAUTION [RFC6064][RFC8859] attribute 3GPP-Asset-Information session, CAUTION [RFC6064][RFC8859] media attribute 3GPP-Integrity-Key session CAUTION [RFC6064][RFC8859] attribute 3GPP-QoE-Metrics session, CAUTION [RFC6064][RFC8859] media attribute 3GPP-SDP-Auth session CAUTION [RFC6064][RFC8859] attribute 3GPP-SRTP-Config media CAUTION [RFC6064][RFC8859] attribute 3gpp-videopostdecbufsize media CAUTION [RFC6064][RFC8859] attribute 3gpp.iut.replication session, TBD [3GPP TS 24.337 10.7.0][Frederic_Firmin][RFC8859] media attribute aal2CPS media CAUTION [RFC3108][RFC8859] attribute aal2CPSSDUrate media CAUTION [RFC3108][RFC8859] attribute aal2sscs3661assured media CAUTION [RFC3108][RFC8859] attribute aal2sscs3661unassured media CAUTION [RFC3108][RFC8859] attribute aal2sscs3662 media CAUTION [RFC3108][RFC8859] attribute aal5sscop media CAUTION [RFC3108][RFC8859] attribute aalApp media CAUTION [RFC3108][RFC8859] attribute aalType media CAUTION [RFC3108][RFC8859] attribute abrParms media CAUTION [RFC3108][RFC8859] attribute abrSetup media CAUTION [RFC3108][RFC8859] attribute acap session, INHERIT [RFC5939][RFC8859] media media, attribute accept-types dcsa TBD [RFC4975][RFC8859][RFC8873] (msrp) media, attribute accept-wrapped-types dcsa TBD [RFC4975][RFC8859][RFC8873] (msrp) attribute acfg media SPECIAL [RFC5939][RFC8859] attribute alt media CAUTION [RFC6064][RFC8859] attribute alt-default-id media CAUTION [RFC6064][RFC8859] attribute alt-group session CAUTION [RFC6064][RFC8859] attribute altc media TRANSPORT [RFC6947][RFC8859] attribute anbr media IDENTICAL [3GPP TS 26.114 v16.3.0][Ozgur_Oyman] attribute anycast media CAUTION [RFC3108][RFC8859] attribute atmmap media CAUTION [RFC3108][RFC8859] attribute atmQOSparms media CAUTION [RFC3108][RFC8859] attribute atmTrfcDesc media CAUTION [RFC3108][RFC8859] [Sonia_Compans][TS 183 063 R3 ETSI TISPAN Technical Specification TS 183 063 "Telecommunications and attribute bc_program session NORMAL Internet converged Services and Protocols for Advanced Networking (TISPAN); IMS-based IPTV stage 3 specification"][RFC8859] [Sonia_Compans][TS 183 063 R3 ETSI TISPAN Technical Specification TS 183 063 "Telecommunications and attribute bc_service session NORMAL Internet converged Services and Protocols for Advanced Networking (TISPAN); IMS-based IPTV stage 3 specification"][RFC8859] [Sonia_Compans][TS 183 063 R3 ETSI TISPAN Technical Specification TS 183 063 "Telecommunications and attribute bc_service_package session NORMAL Internet converged Services and Protocols for Advanced Networking (TISPAN); IMS-based IPTV stage 3 specification"][RFC8859] attribute bcap session, INHERIT [RFC7006][RFC8859] media attribute bcastversion session NORMAL [RFC5159][RFC8859] attribute bcob media CAUTION [RFC3108][RFC8859] attribute bearerSigIE media CAUTION [RFC3108][RFC8859] attribute bearerType media CAUTION [RFC3108][RFC8859] attribute bfcpver media TBD [RFC8856] attribute bundle-only media NORMAL [RFC9143] attribute bw-info media IDENTICAL-PER-PT [3GPP TS 26.114 v16.3.0][Ozgur_Oyman] attribute cache media CAUTION [RFC3108][RFC8859] attribute calgextmap session, NORMAL [RFC7266][RFC8859] media attribute candidate media TRANSPORT [RFC8839][RFC8859] attribute capability media CAUTION [RFC3108][RFC8859] attribute cat session NORMAL [RFC8866][RFC8859] attribute cbrRate media CAUTION [RFC3108][RFC8859] attribute ccap session, IDENTICAL [RFC7006][RFC8859] media attribute ccc_list session NORMAL [3GPP TS 26.114 v16.3.0][_3GPP_Specifications_Manager] attribute cdsc session, NORMAL [RFC3407][RFC8859] media attribute cfw-id media NORMAL [RFC6230][RFC8859] attribute chain media CAUTION [RFC3108][RFC8859] attribute channel media NORMAL [RFC6787][RFC8859] attribute charset session NORMAL [RFC8866][RFC8859] attribute charset:iso8895-1 session NORMAL [RFC8866][RFC8859] attribute chatroom media TBD [RFC7701][RFC8859] attribute clir session, TBD [RFC2848][RFC8859] media attribute clkrec media CAUTION [RFC3108][RFC8859] attribute cmid media NORMAL [RFC6787][RFC8859] attribute cname source NORMAL [RFC5576][RFC8859] attribute codecconfig media CAUTION [RFC3108][RFC8859] attribute conf media CAUTION [RFC3312][RFC8859] attribute confid media TBD [RFC8856][RFC8859] attribute connection session, TRANSPORT [RFC4145][RFC8859] media attribute content media NORMAL [RFC4796][RFC8859] attribute content-desc session, TBD [RFC-mehta-rmt-flute-sdp-05][RFC8859] media attribute control session, CAUTION [RFC2326][RFC7826][RFC8859] media attribute cpar session, INHERIT [RFC3407][RFC8859] media attribute cparmax session, SPECIAL [RFC3407][RFC8859] media attribute cparmin session, SPECIAL [RFC3407][RFC8859] media attribute cpsSDUsize media CAUTION [RFC3108][RFC8859] attribute creq session, NORMAL [RFC5939][RFC8859] media attribute cryptex session, TRANSPORT [RFC9335] media attribute crypto media TRANSPORT [RFC4568][RFC8859] attribute cs-correlation media TBD [RFC7195][RFC8859] attribute csup session, NORMAL [RFC5939][RFC8859] media attribute curr media CAUTION [RFC3312][RFC8859] attribute dccp-port media CAUTION [RFC6773][RFC8859] attribute dccp-service-code media CAUTION [RFC5762][RFC8859] attribute dcmap media SPECIAL [RFC8864] attribute dcsa media SPECIAL [RFC8864] attribute depend media IDENTICAL-PER-PT [RFC5583][RFC8859] attribute des media CAUTION [RFC3312][RFC8859] attribute dsel media CAUTION [RFC3108][RFC8859] attribute duplication-delay session, NORMAL [RFC7197][RFC8859] media attribute ebuacip media TBD [EBU Tech 3368 - Audio Contribution over IP – Profiles][Felix_Poulin][RFC8859] attribute ecan media CAUTION [RFC3108][RFC8859] attribute ecn-capable-rtp media IDENTICAL [RFC6679][RFC8859] attribute eecid media CAUTION [RFC3108][RFC8859] attribute end-of-candidates session, IDENTICAL [RFC8840] media attribute etag session, CAUTION [RFC2326][RFC8859] media attribute extmap session, SPECIAL [RFC8285][RFC8859] media attribute extmap-allow-mixed session, IDENTICAL [RFC8285] media attribute fec media CAUTION [RFC3108][RFC8859] attribute FEC media NORMAL [RFC-mehta-rmt-flute-sdp-05][RFC8859] attribute FEC-declaration session, TBD [RFC-mehta-rmt-flute-sdp-05][RFC8859] media attribute FEC-OTI-extension session, TBD [RFC-mehta-rmt-flute-sdp-05][RFC8859] media attribute fec-repair-flow media SPECIAL [RFC6364][RFC8859] attribute fec-source-flow media SPECIAL [RFC6364][RFC8859] media, attribute file-date dcsa TBD [RFC5547][RFC8859][RFC8873] (msrp) media, attribute file-disposition dcsa TBD [RFC5547][RFC8859][RFC8873] (msrp) media, attribute file-icon dcsa TBD [RFC5547][RFC8859][RFC8873] (msrp) media, attribute file-range dcsa TBD [RFC5547][RFC8859][RFC8873] (msrp) media, attribute file-selector dcsa TBD [RFC5547][RFC8859][RFC8873] (msrp) media, attribute file-transfer-id dcsa TBD [RFC5547][RFC8859][RFC8873] (msrp) attribute fingerprint session, TRANSPORT [RFC8122][RFC8859] media attribute floorctrl media TBD [RFC8856][RFC8859] attribute floorid media TBD [RFC8856][RFC8859] attribute flute-ch session, TBD [RFC-mehta-rmt-flute-sdp-05][RFC8859] media attribute flute-tsi session, TBD [RFC-mehta-rmt-flute-sdp-05][RFC8859] media media, attribute fmtp source, IDENTICAL-PER-PT [RFC5576][RFC8866][RFC8859][RFC8865] dcsa (t140) attribute framerate media IDENTICAL-PER-PT [RFC8866][RFC8859] attribute framesize media CAUTION [RFC6064][RFC8859] attribute fsel media CAUTION [RFC3108][RFC8859] attribute gc media CAUTION [RFC3108][RFC8859] attribute gpmd media TBD [ITU-T Rec. V.150.1][ITU-T Rec. V.152][Simao_Campos-Neto] attribute group session NORMAL [RFC5888][RFC8859] attribute h248item session, SPECIAL [ITU-T H.248.15][RFC8859] media media, attribute hlang-recv dcsa NORMAL [RFC8373][RFC8865] (t140) media, attribute hlang-send dcsa NORMAL [RFC8373][RFC8865] (t140) attribute icap session, NORMAL [RFC7006][RFC8859] media attribute ice-lite session NORMAL [RFC8839][RFC8859] attribute ice-mismatch media NORMAL [RFC8839][RFC8859] attribute ice-options session NORMAL [RFC8839][RFC8859] attribute ice-pacing session NORMAL [RFC8839] attribute ice-pwd session, TRANSPORT [RFC8839][RFC8859] media attribute ice-ufrag session, TRANSPORT [RFC8839][RFC8859] media attribute identity session NORMAL [RFC8827] attribute ike-setup session, IDENTICAL [RFC6193][RFC8859] media attribute imageattr media IDENTICAL-PER-PT [RFC6236][RFC8859] session, media, attribute inactive dcsa NORMAL [RFC8866][RFC8859][RFC8865][RFC8873] (t140), dcsa (msrp) attribute ipbcp session SPECIAL [ITU-T Recommendation Q.1970, "BICC IP bearer control protocol" (07/2001)][RFC8859] attribute isup_usi media CAUTION [RFC3108][RFC8859] attribute key-mgmt session, IDENTICAL [RFC4567][RFC8859] media attribute keywds session NORMAL [RFC8866][RFC8859] attribute label media NORMAL [RFC4574][RFC8859] attribute lang session, NORMAL [RFC8866][RFC8859] media attribute lcfg media SPECIAL [RFC6871][RFC8859] attribute lij media CAUTION [RFC3108][RFC8859] attribute loopback media NORMAL [RFC6849][RFC8859] attribute loopback-mirror media NORMAL [RFC6849][RFC8859] attribute loopback-source media NORMAL [RFC6849][RFC8859] attribute max-message-size media CAUTION [RFC8841] media, attribute max-size dcsa TBD [RFC4975][RFC8859][RFC8873] (msrp) attribute maxmptime media TBD [ITU-T Recommendation V.152 "Procedures for supporting voice-band data over IP networks", September 2010][Simao_Campos-Neto] attribute maxprate session, SPECIAL [RFC3890][RFC8859] media attribute maxptime media IDENTICAL-PER-PT [RFC8866][RFC8859] attribute mbms-flowid media CAUTION [RFC6064][RFC8859] attribute mbms-mode session, CAUTION [RFC6064][RFC8859] media attribute mbms-repair session, CAUTION [RFC6064][RFC8859] media session, attribute mediaclk media, NORMAL [RFC7273][RFC8859] source attribute mfcap session, IDENTICAL-PER-PT [RFC6871][RFC8859] media attribute mid media NORMAL [RFC5888][RFC8859] attribute mscap session, INHERIT [RFC6871][RFC8859] media attribute msid media NORMAL [RFC8830] media, attribute msrp-cema dcsa TBD [RFC6714][RFC8859][RFC8873] (msrp) attribute mtag session, CAUTION [RFC7826][RFC8859] media attribute multicast-rtcp session, IDENTICAL [RFC6128][RFC8859] media attribute omcap session, NORMAL [RFC6871][RFC8859] media attribute omr-codecs media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Frederic_Firmin][RFC8859] attribute omr-m-att media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Frederic_Firmin][RFC8859] attribute omr-m-bw media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Frederic_Firmin][RFC8859] attribute omr-m-cksum media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Frederic_Firmin][RFC8859] attribute omr-s-att media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Frederic_Firmin][RFC8859] attribute omr-s-bw media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Frederic_Firmin][RFC8859] attribute omr-s-cksum media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Frederic_Firmin][RFC8859] attribute onewaySel media CAUTION [RFC3108][RFC8859] attribute orient media NORMAL [RFC8866][RFC8859] attribute orient:landscape media NORMAL [RFC8866][RFC8859] attribute orient:portrait media NORMAL [RFC8866][RFC8859] attribute orient:seascape media NORMAL [RFC8866][RFC8859] media, attribute path dcsa TBD [RFC4975][RFC8859][RFC8873] (msrp) attribute pcfg media SPECIAL [RFC5939][RFC8859] attribute phone-context session, TBD [RFC2848][RFC8859] media attribute pmft media TBD [ITU-T Recommendation V.152 "Procedures for supporting voice-band data over IP networks", September 2010][Simao_Campos-Neto] attribute portmapping-req media CAUTION [RFC6284][RFC8859] attribute predefined_ROI media IDENTICAL-PER-PT [3GPP TS 26.114 v16.3.0][_3GPP_Specifications_Manager] attribute previous-ssrc source NORMAL [RFC5576][RFC8859] attribute profileDesc media CAUTION [RFC3108][RFC8859] attribute prtfl media CAUTION [RFC3108][RFC8859] [Sonia_Compans][TS 183 063 R3 ETSI TISPAN Technical Specification TS 183 063 "Telecommunications and attribute PSCid session NORMAL Internet converged Services and Protocols for Advanced Networking (TISPAN); IMS-based IPTV stage 3 specification"][RFC8859] attribute psk-fingerprint session, IDENTICAL [RFC6193][RFC8859] media attribute ptime media IDENTICAL-PER-PT [RFC8866][RFC8859] attribute Q763-INN session, TBD [RFC2848][RFC8859] media attribute Q763-nature session, TBD [RFC2848][RFC8859] media attribute Q763-plan session, TBD [RFC2848][RFC8859] media attribute qos-mech-recv session, TRANSPORT [RFC5432][RFC8859] media attribute qos-mech-send session, TRANSPORT [RFC5432][RFC8859] media attribute qosClass media CAUTION [RFC3108][RFC8859] attribute quality media NORMAL [RFC8866][RFC8859] attribute rams-updates media CAUTION [RFC6285][RFC8859] attribute range session, CAUTION [RFC2326][RFC7826][RFC8859] media attribute record session, TBD [RFC7866][RFC8859] media attribute recordpref session, TBD [RFC7866][RFC8859] media session, media, attribute recvonly dcsa NORMAL [RFC8866][RFC8859][RFC8865][RFC8873] (t140), dcsa (msrp) attribute remote-candidates media TRANSPORT [RFC8839][RFC8859] attribute repair-window media SPECIAL [RFC6364][RFC8859] attribute require session, TBD [RFC2848][RFC8859] media attribute resource media NORMAL [RFC6787][RFC8859] attribute rid media SPECIAL [RFC8851] attribute rmcap session, IDENTICAL-PER-PT [RFC6871][RFC8859] media attribute rtcp media TRANSPORT [RFC3605][RFC8859] attribute rtcp-fb media IDENTICAL-PER-PT [RFC4585][RFC8859] attribute rtcp-idms media NORMAL [RFC7272][RFC8859] attribute rtcp-mux media IDENTICAL [RFC5761][RFC8035][RFC8859] attribute rtcp-mux-only media IDENTICAL [RFC8858] attribute rtcp-rgrp session, IDENTICAL [RFC8861][RFC8859] media attribute rtcp-rsize media IDENTICAL [RFC5506][RFC8859] attribute rtcp-unicast media IDENTICAL [RFC5760][RFC8859] attribute rtcp-xr session, NORMAL [RFC3611][RFC8859] media attribute rtpmap media IDENTICAL-PER-PT [RFC8866][RFC8859] attribute rtpred1 media CAUTION [2][RFC8859] attribute rtpred2 media CAUTION [2][RFC8859] attribute rtsp-ice-d-m session TBD [RFC7825][RFC8859] attribute rtt-mixer media NORMAL [RFC9071, Section 2.3] attribute sbc media CAUTION [RFC3108][RFC8859] attribute sctp-port media CAUTION [RFC8841] attribute sdplang session, NORMAL [RFC8866][RFC8859] media attribute secondary-realm media TRANSPORT [TS 24.229 v10.7.0 table 7.5.2][Frederic_Firmin][RFC8859] session, media, attribute sendonly dcsa NORMAL [RFC8866][RFC8859][RFC8865][RFC8873] (t140), dcsa (msrp) session, media, attribute sendrecv dcsa NORMAL [RFC8866][RFC8859][RFC8865][RFC8873] (t140), dcsa (msrp) attribute sescap session CAUTION [RFC6871][RFC8859] session, attribute setup media, TRANSPORT [RFC4145][RFC8859][RFC8873] dcsa (msrp) attribute silenceSupp media CAUTION [RFC3108][RFC8859] attribute simulcast media NORMAL [RFC8853] attribute source-filter session, IDENTICAL [RFC4570][RFC8859] media attribute sqn session, NORMAL [RFC3407][RFC8859] media attribute SRTPAuthentication media TBD [RFC5159][RFC8859] attribute SRTPROCTxRate media TBD [RFC5159][RFC8859] attribute ssrc media NORMAL [RFC5576][RFC8859] attribute ssrc-group media NORMAL [RFC5576][RFC8859] attribute stc media CAUTION [RFC3108][RFC8859] attribute stkmstream session, NORMAL [RFC5159][RFC8859] media attribute structure media CAUTION [RFC3108][RFC8859] attribute suspended session, TBD [NENA STA-010.2-2016][Brian_Rosen][RFC8859] media attribute T38FaxFillBitRemoval media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC8859] attribute T38FaxMaxBuffer media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC8859] attribute T38FaxMaxDatagram media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC8859] attribute T38FaxMaxIFP media TBD [ITU-T Recommendation T.38 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][Simao_Campos-Neto][RFC8859] attribute T38FaxRateManagement media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC8859] attribute T38FaxTranscodingJBIG media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC8859] attribute T38FaxTranscodingMMR media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC8859] attribute T38FaxUdpEC media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC8859] attribute T38FaxUdpECDepth media TBD [ITU-T Recommendation T.38 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][Simao_Campos-Neto][RFC8859] attribute T38FaxUdpFECMaxSpan media TBD [ITU-T Recommendation T.38 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][Simao_Campos-Neto][RFC8859] attribute T38FaxVersion media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC8859] attribute T38MaxBitRate media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC8859] attribute T38ModemType media TBD [ITU-T Recommendation T.38 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][Simao_Campos-Neto][RFC8859] attribute T38VendorInfo media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', February 2000, July 2005.][RFC8859] attribute tcap session, INHERIT [RFC5939][RFC8859] media attribute tls-id media IDENTICAL [RFC8842] attribute tool session NORMAL [RFC8866][RFC8859] attribute tra-att session, NORMAL [http://www.3gpp.org/ftp/Specs/html-info/24229.htm][http://www.3gpp.org/ftp/Specs/html-info/24371.htm] media attribute tra-bw session, NORMAL [http://www.3gpp.org/ftp/Specs/html-info/24229.htm][http://www.3gpp.org/ftp/Specs/html-info/24371.htm] media attribute tra-contact session, NORMAL [http://www.3gpp.org/ftp/Specs/html-info/24229.htm][http://www.3gpp.org/ftp/Specs/html-info/24371.htm] media attribute tra-m-line media NORMAL [http://www.3gpp.org/ftp/Specs/html-info/24229.htm][http://www.3gpp.org/ftp/Specs/html-info/24371.htm] attribute tra-media-line-number session NORMAL [http://www.3gpp.org/ftp/Specs/html-info/24229.htm][http://www.3gpp.org/ftp/Specs/html-info/24371.htm] attribute tra-SCTP-association media NORMAL [http://www.3gpp.org/ftp/Specs/html-info/24229.htm][http://www.3gpp.org/ftp/Specs/html-info/24371.htm] session, attribute ts-refclk media, NORMAL [RFC7273][RFC8859] source attribute type session NORMAL [RFC8866][RFC8859] attribute type:H332 session NORMAL [ITU Recommendation H.332][RFC8859] attribute type:broadcast session NORMAL [RFC8866][RFC8859] attribute type:meeting session NORMAL [RFC8866][RFC8859] attribute type:moderated session NORMAL [RFC8866][RFC8859] attribute type:test session NORMAL [RFC8866][RFC8859] attribute uiLayer1_Prot media CAUTION [RFC3108][RFC8859] attribute upcc media CAUTION [RFC3108][RFC8859] attribute userid media TBD [RFC8856][RFC8859] attribute vbd (OBSOLETE) media TBD [ITU-T Recommendation V.152 "Procedures for supporting voice-band data over IP networks", September 2010][Simao_Campos-Neto] attribute visited-realm media TRANSPORT [TS 24.229 v10.7.0 table 7.5.2][Frederic_Firmin][RFC8859] attribute vndpar session, TBD [ITU-T Rec. V.150.1][ITU-T Rec. V.152][Simao_Campos-Neto] media attribute vsel media CAUTION [RFC3108][RFC8859] attribute websocket-uri media CAUTION [RFC8124] attribute X-decbyterate media CAUTION [RFC6064][RFC8859] attribute X-initpostdecbufperiod media CAUTION [RFC6064][RFC8859] attribute X-initpredecbufperiod media CAUTION [RFC6064][RFC8859] attribute X-predecbufsize media CAUTION [RFC6064][RFC8859] attribute zrtp-hash media TRANSPORT [RFC6189][RFC8859] content SDP Parameters Registration Procedure(s) Specification Required Expert(s) Christer Holmberg Reference [RFC4796][RFC8859] Available Formats [IMG] CSV Type SDP Name Description Mux Category Reference content slides Presentation slides NORMAL [RFC4796][RFC8859] content speaker Image from the speaker NORMAL [RFC4796][RFC8859] content sl Sign language NORMAL [RFC4796][RFC8859] content main Main media stream NORMAL [RFC4796][RFC8859] content alt Alternative media stream NORMAL [RFC4796][RFC8859] Stream associated with the 3GPP content g.3gpp.cat Customized Alerting Ringtone (CAT) NORMAL [3GPP TS 24.182 v11.2.0][Frederic_Firmin][RFC8859] service Stream associated with the 3GPP [3GPP TS 24.183 v9.10.0 annex content g.3gpp.crs Customized Ringing Signal (CRS) NORMAL E][Frederic_Firmin][RFC8859] service Stream associated with video content g.3gpp.announcement-no-confirmation announcement service without user NORMAL [3GPP TS 24.229] confirmation Semantics for the "group" SDP Attribute Registration Procedure(s) Standards Action Reference [RFC5888][RFC8859] Available Formats [IMG] CSV Semantics Token Mux Category Reference Lip Synchronization LS NORMAL [RFC5888][RFC8859] Flow Identification FID NORMAL [RFC5888][RFC8859] Single Reservation flow SRF NORMAL [RFC3524][RFC8859] Alternative Network Address Types ANAT CAUTION [RFC4091][RFC8859] Forward Error Correction (Deprecated) FEC NORMAL [RFC5956][RFC8859] Forward Error Correction FR FEC-FR NORMAL [RFC5956][RFC8859] Composite Session CS NORMAL [RFC-mehta-rmt-flute-sdp-05][RFC8859] Decoding Dependency DDP NORMAL [RFC5583][RFC8859] Duplication DUP NORMAL [RFC7104][RFC8859] Splice SPLICE TBD [RFC8286][RFC8859] Media bundling BUNDLE NORMAL [RFC9143] CLUE-controlled "m=" line CLUE NORMAL [RFC8848] "rtcp-fb" Attribute Values Registration Procedure(s) First Come First Served with permanent, stable, and publically accessible document. Reference [RFC4585][RFC8859] Available Formats [IMG] CSV Value Name Long Name Mux Category Reference ack Positive acknowledgement IDENTICAL-PER-PT [RFC4585][RFC8859] app Application-defined parameter SPECIAL [RFC4585][RFC8859] ccm Codec Control Commands and Indications IDENTICAL-PER-PT [RFC5104][RFC8859] nack Negative Acknowledgement IDENTICAL-PER-PT [RFC4585][RFC8859] trr-int Minimal receiver report interval IDENTICAL-PER-PT [RFC4585][RFC8859] 3gpp-roi-arbitrary Video region-of-interest (ROI) arbitrarily selected by the endpoint IDENTICAL-PER-PT [3GPP TS 26.114 v16.3.0][Ozgur_Oyman] 3gpp-roi-predefined Video region-of-interest (ROI) pre-defined by the sender and selected IDENTICAL-PER-PT [3GPP TS 26.114 v16.3.0][Ozgur_Oyman] by the endpoint 3gpp-delay-budget Available or requested delay budget specified in milliseconds IDENTICAL-PER-PT [3GPP TS 26.114 v16.3.0][Ozgur_Oyman] 3gpp-viewport Viewport feedback for viewport-dependent 360-degree video IDENTICAL-PER-PT [3GPP TS 26.114] "ack" and "nack" Attribute Values Registration Procedure(s) First Come First Served with a permanent, stable, and publically accessible document Reference [RFC4585][RFC8859] Available Formats [IMG] CSV Value Name Long Name Usable with Mux Reference sli Slice Loss Indication nack IDENTICAL-PER-PT [RFC4585][RFC8859] pli Picture Loss Indication nack IDENTICAL-PER-PT [RFC4585][RFC8859] rpsi Reference Picture Selection Indication ack, nack IDENTICAL-PER-PT [RFC4585][RFC8859] app Application layer feedback ack, nack SPECIAL [RFC4585][RFC8859] rai Rapid Acquisition Indication nack IDENTICAL-PER-PT [RFC6285][RFC8859] tllei Transport-Layer Third-Party Loss Early Indication nack IDENTICAL-PER-PT [RFC6642][RFC8859] pslei Payload-Specific Third-Party Loss Early Indication nack IDENTICAL-PER-PT [RFC6642][RFC8859] ecn Explicit Congestion Notification nack IDENTICAL [RFC6679][RFC8859] ccfb Congestion Control Feedback ack IDENTICAL-PER-PT [RFC8888] "depend" SDP Attribute Values Registration Procedure(s) Specification Required Expert(s) Stephan Wenger Reference [RFC5583][RFC8859] Available Formats [IMG] CSV Token Semantics Mux Category Reference lay Layered decoding dependency IDENTICAL-PER-PT [RFC5583][RFC8859] mdc Multi descriptive decoding dependency IDENTICAL-PER-PT [RFC5583][RFC8859] "cs-correlation" Attribute Values Registration Procedure(s) Specification Required Expert(s) Bo Burman Reference [RFC7195][RFC8859] Available Formats [IMG] CSV Value Description Mux Category Reference callerid Caller ID TBD [RFC7195][RFC8859] uuie User-User Information Element TBD [RFC7195][RFC8859] dtmf Dual-tone Multi-Frequency TBD [RFC7195][RFC8859] external External TBD [RFC7195][RFC8859] Semantics for the "ssrc-group" SDP Attribute Registration Procedure(s) Standards Action Reference [RFC5576][RFC8859] Available Formats [IMG] CSV Token Semantics Mux Category Reference FID Flow Identification NORMAL [RFC5576][RFC8859] FEC Forward Error Correction NORMAL [RFC5576][RFC8859] FEC-FR Forward Error Correction FR NORMAL [RFC5956][RFC8859] DUP Duplication NORMAL [RFC7104][RFC8859] SDP/RTSP key management protocol identifiers Registration Procedure(s) Specification Required Expert(s) Magnus Westerlund Reference [RFC4567][RFC8859] Note This registry of the key management protocol identifier, KMPID, has a name space that is shared between the SDP "key-mgmt" attribute and RTSP header "keymgmt". Available Formats [IMG] CSV Value Name Long Name Mux Category Reference mikey Multimedia Internet KEYing IDENTICAL [RFC4567][RFC8859] Codec Control Messages Registration Procedure(s) Specification Required Expert(s) Stephan Wenger Reference [RFC5104][RFC8859] Available Formats [IMG] CSV Value Name Long Name Usable with Mux Reference fir Full Intra Request Command ccm IDENTICAL-PER-PT [RFC5104][RFC8859] tmmbr Temporary Maximum Media Stream Bit Rate ccm IDENTICAL-PER-PT [RFC5104][RFC8859] tstr Temporal-Spatial Trade-off ccm IDENTICAL-PER-PT [RFC5104][RFC8859] vbcm H.271 video back channel messages ccm IDENTICAL-PER-PT [RFC5104][RFC8859] pause Media Pause/Resume ccm TBD [RFC7728][RFC8859] lrr Layer Refresh Request Command ccm IDENTICAL-PER-PT [RFC-ietf-avtext-lrr-07] QoS Mechanism Tokens Registration Procedure(s) Specification Required Expert(s) Christer Holmberg Reference [RFC5432][RFC8859] Available Formats [IMG] CSV QoS Mechanism Mux Category Reference rsvp TRANSPORT [RFC5432][RFC8859] nsis TRANSPORT [RFC5432][RFC8859] SDP Capability Negotiation Option Tags Registration Procedure(s) IETF Review Reference [RFC5939][RFC8859] Available Formats [IMG] CSV Option Tag Mux Category Reference cap-v0 NORMAL [RFC5939][RFC8859] med-v0 NORMAL [RFC6871][RFC8859] bcap-v0 NORMAL [RFC7006][RFC8859] ccap-v0 NORMAL [RFC7006][RFC8859] icap-v0 NORMAL [RFC7006][RFC8859] SDP Capability Negotiation Configuration Parameters Registry Registration Procedure(s) IETF Review Reference [RFC5939][RFC6871] Available Formats [IMG] CSV Encoding Name Descriptive Name Potential Configuration Actual Configuration Definition Latent Configuration Definition Definition a Attribute Configuration [RFC5939] [RFC5939] [RFC6871] b Bandwidth [RFC7006] [RFC7006] [RFC7006] c Connection Data [RFC7006] [RFC7006] [RFC7006] i Title [RFC7006] [RFC7006] [RFC7006] m Media Configuration [RFC6871] [RFC6871] [RFC6871] mt Media Type [RFC6871] [RFC6871] [RFC6871] pt Payload Type Number Mapping [RFC6871] [RFC6871] [RFC6871] t Transport Protocol Configuration [RFC5939] [RFC5939] [RFC6871] Timestamp Reference Clock Source Parameters Registration Procedure(s) Specification Required Expert(s) Magnus Westerlund Reference [RFC7273][RFC8859] Available Formats [IMG] CSV Name Long Name Mux Category Reference ntp Network Time Protocol NORMAL [RFC7273, section 4][RFC8859] ptp Precision Time Protocol NORMAL [RFC7273, section 4][RFC8859] gps Global Positioning System NORMAL [RFC7273, section 4][RFC8859] gal Galileo NORMAL [RFC7273, section 4][RFC8859] glonass Global Navigation Satellite System NORMAL [RFC7273, section 4][RFC8859] local Local Clock NORMAL [RFC7273, section 4][RFC8859] private Private Clock NORMAL [RFC7273, section 4][RFC8859] Media Clock Source Parameters Registration Procedure(s) Specification Required Expert(s) Magnus Westerlund Reference [RFC7273][RFC8859] Available Formats [IMG] CSV Name Long Name Mux Category Reference sender Asynchronously Generated Media Clock NORMAL [RFC7273, section 5][RFC8859] direct Direct-Referenced Media Clock NORMAL [RFC7273, section 5][RFC8859] IEEE1722 IEEE1722 Media Stream Identifier NORMAL [RFC7273, section 5][RFC8859] Multiplexing Categories Registration Procedure(s) Standards Action Reference [RFC8859] Available Formats [IMG] CSV Multiplexing Categories Reference NORMAL [RFC8859] CAUTION [RFC8859] IDENTICAL [RFC8859] TRANSPORT [RFC8859] SUM [RFC8859] INHERIT [RFC8859] IDENTICAL-PER-PT [RFC8859] SPECIAL [RFC8859] TBD [RFC8859] association-usage Name Registry Registration Procedure(s) First Come First Served Reference [RFC8841] Available Formats [IMG] CSV Name Reference Change Controller webrtc-datachannel [RFC8841][RFC8832] IESG RID Attribute Parameters Registration Procedure(s) Specification Required Expert(s) Adam Roach Reference [RFC8851] Available Formats [IMG] CSV RID Parameter Name Reference pt [RFC8851] max-width [RFC8851] max-height [RFC8851] max-fps [RFC8851] max-fs [RFC8851] max-br [RFC8851] max-pps [RFC8851] max-bpp [RFC8851] depend [RFC8851] Candidate Attribute Extensions Registration Procedure(s) Specification Required Expert(s) Christer Holmberg Reference [RFC8839] Name Description Change Controller Reference No registrations at this time. Contact Information ID Name Contact URI Last Updated [_3GPP_Specifications_Manager] 3GPP Specifications Manager mailto:3gppContact&etsi.org 2017-06-16 [Brian_Rosen] Brian Rosen mailto:br&brianrosen.net 2016-10-11 [Felix_Poulin] Felix Poulin, EBU-FNS Coordinator mailto:poulin&ebu.ch 2016-11-17 [Frederic_Firmin] Frederic Firmin mailto:frederic.firmin&etsi.org 2020-09-04 [Ozgur_Oyman] Ozgur Oyman mailto:ozgur.oyman&intel.com 2019-11-06 [Simao_Campos-Neto] Simão Campos-Neto mailto:simao.campos&itu.int 2019-07-30 [Sonia_Compans] Sonia Compans mailto:Sonia.Compans&etsi.org 2010-11-24 Footnotes [1] historic [2] historic; use fmtp as per [RFC2198] Licensing Terms