Session Description Protocol (SDP) Parameters

Created
2001-06-15
Last Updated
2026-09-01
Available Formats

XML
HTML
TXT

Registries Included Below

media

Registration Procedure(s)
Standards Action
Reference
[RFC 8866]
Available Formats

CSV
Type SDP Name Reference
media audio [RFC 8866]
media video [RFC 8866]
media text [RFC 8866]
media application [RFC 8866]
media message [RFC 8866]
media image [RFC 6466]
media haptics [RFC 9993]

proto

Registration Procedure(s)
RFC Required
Reference
[RFC 8866]
Note
Standards Track RFC preferred.
Available Formats

CSV
Type SDP Name Reference
proto RTP/AVP [RFC 8866]
proto udp [RFC 8866]
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 [RFC 4145]
proto RTP/AVPF [RFC 4585]
proto TCP/RTP/AVP [RFC 4571]
proto RTP/SAVP [RFC 3711]
proto TCP/BFCP [RFC 8856]
proto TCP/TLS/BFCP [RFC 8856]
proto TCP/TLS [RFC 8122]
proto FLUTE/UDP [RFC-mehta-rmt-flute-sdp-05]
proto TCP/MSRP [RFC 4975]
proto TCP/TLS/MSRP [RFC 4975]
proto DCCP [RFC 5762]
proto DCCP/RTP/AVP [RFC 5762]
proto DCCP/RTP/SAVP [RFC 5762]
proto DCCP/RTP/AVPF [RFC 5762]
proto DCCP/RTP/SAVPF [RFC 5762]
proto RTP/SAVPF [RFC 5124]
proto UDP/TLS/RTP/SAVP [RFC 5764]
proto DCCP/TLS/RTP/SAVP [RFC 5764]
proto UDP/TLS/RTP/SAVPF [RFC 5764]
proto DCCP/TLS/RTP/SAVPF [RFC 5764]
proto UDP/MBMS-FEC/RTP/AVP [RFC 6064]
proto UDP/MBMS-FEC/RTP/SAVP [RFC 6064]
proto UDP/MBMS-REPAIR [RFC 6064]
proto FEC/UDP [RFC 6364]
proto UDP/FEC [RFC 6364]
proto TCP/MRCPv2 [RFC 6787]
proto TCP/TLS/MRCPv2 [RFC 6787]
proto PSTN [RFC 7195]
proto UDP/TLS/UDPTL [RFC 7345]
proto voice [RFC 2848]
proto fax [RFC 2848]
proto pager [RFC 2848]
proto TCP/RTP/AVPF [RFC 7850]
proto TCP/RTP/SAVP [RFC 7850]
proto TCP/RTP/SAVPF [RFC 7850]
proto TCP/DTLS/RTP/SAVP [RFC 7850]
proto TCP/DTLS/RTP/SAVPF [RFC 7850]
proto TCP/TLS/RTP/AVP [RFC 7850]
proto TCP/TLS/RTP/AVPF [RFC 7850]
proto TCP/WS/BFCP [RFC 8857]
proto TCP/WSS/BFCP [RFC 8857]
proto UDP/DTLS/SCTP [RFC 8841]
proto TCP/DTLS/SCTP [RFC 8841]
proto TCP/DTLS/BFCP [RFC 8856]
proto UDP/BFCP [RFC 8856]
proto UDP/TLS/BFCP [RFC 8856]

bwtype

Registration Procedure(s)
Standards Action
Reference
[RFC 8866][RFC 8859]
Available Formats

CSV
Type SDP Name Mux Category Reference
bwtype CT NORMAL [RFC 8866][RFC 8859]
bwtype AS SUM [RFC 8866][RFC 8859]
bwtype RS SUM [RFC 3556][RFC 8859]
bwtype RR SUM [RFC 3556][RFC 8859]
bwtype TIAS SPECIAL [RFC 3890][RFC 8859]

nettype

Registration Procedure(s)
RFC Required
Reference
[RFC 8866]
Available Formats

CSV
Type SDP Name Usable addrtype Values Reference
nettype IN IP4, IP6 [RFC 8866]
nettype TN RFC2543 [RFC 2848]
nettype ATM NSAP, GWID, E164 [RFC 3108]
nettype PSTN E164 [RFC 7195]

addrtype

Registration Procedure(s)
RFC Required
Reference
[RFC 8866]
Available Formats

CSV
Type SDP Name Reference
addrtype IP4 [RFC 8866]
addrtype IP6 [RFC 8866]
addrtype NSAP [RFC 3108]
addrtype GWID [RFC 3108]
addrtype E164 [RFC 7195][RFC 3108]

enckey

Registration Procedure(s)
REGISTRY OBSOLETED - No further registrations accepted
Reference
[RFC 8866]
Available Formats

CSV
Type SDP Name Reference
enckey clear [RFC 8866]
enckey base64 [RFC 8866]
enckey uri [RFC 8866]
enckey prompt [RFC 8866]

attribute-name (formerly "att-field")

Registration Procedure(s)
Specification Required
Expert(s)
Flemming Andreasen
Reference
[RFC 8866][RFC 8864][RFC 8859]
Available Formats

CSV
Type SDP Name Usage Level Mux Category Reference
attribute 3ge2ae media IDENTICAL [3GPP TS 24.229 12.14.0][Dongwook_Kim]
attribute 3gpp_MaxRecvSDUSize session, media NORMAL [3GPP TS 26.114 v16.3.0][_3GPP_Specifications_Manager]
attribute 3gpp_mtsi_app_adapt media IDENTICAL-PER-PT [3GPP TS 26.114 v16.3.0][Ozgur_Oyman]
attribute 3gpp_sync_info session, media NORMAL [3GPP TS 26.114 v16.3.0][_3GPP_Specifications_Manager]
attribute 3GPP-Adaptation-Support media CAUTION [RFC 6064][RFC 8859]
attribute 3GPP-Asset-Information session, media CAUTION [RFC 6064][RFC 8859]
attribute 3GPP-Integrity-Key session CAUTION [RFC 6064][RFC 8859]
attribute 3GPP-QoE-Metrics session, media CAUTION [RFC 6064][RFC 8859]
attribute 3GPP-SDP-Auth session CAUTION [RFC 6064][RFC 8859]
attribute 3GPP-SRTP-Config media CAUTION [RFC 6064][RFC 8859]
attribute 3gpp-videopostdecbufsize media CAUTION [RFC 6064][RFC 8859]
attribute 3gpp.iut.replication session, media TBD [3GPP TS 24.337 10.7.0][Dongwook_Kim][RFC 8859]
attribute aal2CPS media CAUTION [RFC 3108][RFC 8859]
attribute aal2CPSSDUrate media CAUTION [RFC 3108][RFC 8859]
attribute aal2sscs3661assured media CAUTION [RFC 3108][RFC 8859]
attribute aal2sscs3661unassured media CAUTION [RFC 3108][RFC 8859]
attribute aal2sscs3662 media CAUTION [RFC 3108][RFC 8859]
attribute aal5sscop media CAUTION [RFC 3108][RFC 8859]
attribute aalApp media CAUTION [RFC 3108][RFC 8859]
attribute aalType media CAUTION [RFC 3108][RFC 8859]
attribute abrParms media CAUTION [RFC 3108][RFC 8859]
attribute abrSetup media CAUTION [RFC 3108][RFC 8859]
attribute acap session, media INHERIT [RFC 5939][RFC 8859]
attribute accept-types media, dcsa (msrp) TBD [RFC 4975][RFC 8859][RFC 8873]
attribute accept-wrapped-types media, dcsa (msrp) TBD [RFC 4975][RFC 8859][RFC 8873]
attribute acfg media SPECIAL [RFC 5939][RFC 8859]
attribute alt media CAUTION [RFC 6064][RFC 8859]
attribute alt-default-id media CAUTION [RFC 6064][RFC 8859]
attribute alt-group session CAUTION [RFC 6064][RFC 8859]
attribute altc media TRANSPORT [RFC 6947][RFC 8859]
attribute anbr media IDENTICAL [3GPP TS 26.114 v16.3.0][Ozgur_Oyman]
attribute anycast media CAUTION [RFC 3108][RFC 8859]
attribute atmmap media CAUTION [RFC 3108][RFC 8859]
attribute atmQOSparms media CAUTION [RFC 3108][RFC 8859]
attribute atmTrfcDesc media CAUTION [RFC 3108][RFC 8859]
attribute bc_program session NORMAL [Sonia_Compans][TS 183 063 R3 ETSI TISPAN Technical Specification TS 183 063 "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); IMS-based IPTV stage 3 specification"][RFC 8859]
attribute bc_service session NORMAL [Sonia_Compans][TS 183 063 R3 ETSI TISPAN Technical Specification TS 183 063 "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); IMS-based IPTV stage 3 specification"][RFC 8859]
attribute bc_service_package session NORMAL [Sonia_Compans][TS 183 063 R3 ETSI TISPAN Technical Specification TS 183 063 "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); IMS-based IPTV stage 3 specification"][RFC 8859]
attribute bcap session, media INHERIT [RFC 7006][RFC 8859]
attribute bcastversion session NORMAL [RFC 5159][RFC 8859]
attribute bcob media CAUTION [RFC 3108][RFC 8859]
attribute bearerSigIE media CAUTION [RFC 3108][RFC 8859]
attribute bearerType media CAUTION [RFC 3108][RFC 8859]
attribute bfcpver media TBD [RFC 8856]
attribute bundle-only media NORMAL [RFC 9143]
attribute bw-info media IDENTICAL-PER-PT [3GPP TS 26.114 v16.3.0][Ozgur_Oyman]
attribute cache media CAUTION [RFC 3108][RFC 8859]
attribute calgextmap session, media NORMAL [RFC 7266][RFC 8859]
attribute candidate media TRANSPORT [RFC 8839][RFC 8859]
attribute capability media CAUTION [RFC 3108][RFC 8859]
attribute cat session NORMAL [RFC 8866][RFC 8859]
attribute cbrRate media CAUTION [RFC 3108][RFC 8859]
attribute ccap session, media IDENTICAL [RFC 7006][RFC 8859]
attribute ccc_list session NORMAL [3GPP TS 26.114 v16.3.0][_3GPP_Specifications_Manager]
attribute cdsc session, media NORMAL [RFC 3407][RFC 8859]
attribute cfw-id media NORMAL [RFC 6230][RFC 8859]
attribute chain media CAUTION [RFC 3108][RFC 8859]
attribute channel media NORMAL [RFC 6787][RFC 8859]
attribute charset session NORMAL [RFC 8866][RFC 8859]
attribute charset:iso8895-1 session NORMAL [RFC 8866][RFC 8859]
attribute chatroom media TBD [RFC 7701][RFC 8859]
attribute clir session, media TBD [RFC 2848][RFC 8859]
attribute clkrec media CAUTION [RFC 3108][RFC 8859]
attribute cmid media NORMAL [RFC 6787][RFC 8859]
attribute cname source NORMAL [RFC 5576][RFC 8859]
attribute codecconfig media CAUTION [RFC 3108][RFC 8859]
attribute conf media CAUTION [RFC 3312][RFC 8859]
attribute confid media TBD [RFC 8856][RFC 8859]
attribute connection session, media TRANSPORT [RFC 4145][RFC 8859]
attribute content media NORMAL [RFC 4796][RFC 8859]
attribute content-desc session, media TBD [RFC-mehta-rmt-flute-sdp-05][RFC 8859]
attribute control session, media CAUTION [RFC 2326][RFC 7826][RFC 8859]
attribute cpar session, media INHERIT [RFC 3407][RFC 8859]
attribute cparmax session, media SPECIAL [RFC 3407][RFC 8859]
attribute cparmin session, media SPECIAL [RFC 3407][RFC 8859]
attribute cpsSDUsize media CAUTION [RFC 3108][RFC 8859]
attribute creq session, media NORMAL [RFC 5939][RFC 8859]
attribute cryptex session, media TRANSPORT [RFC 9335]
attribute crypto media TRANSPORT [RFC 4568][RFC 8859]
attribute cs-correlation media TBD [RFC 7195][RFC 8859]
attribute csup session, media NORMAL [RFC 5939][RFC 8859]
attribute curr media CAUTION [RFC 3312][RFC 8859]
attribute dccp-port media CAUTION [RFC 6773][RFC 8859]
attribute dccp-service-code media CAUTION [RFC 5762][RFC 8859]
attribute dcmap media SPECIAL [RFC 8864]
attribute dcsa media SPECIAL [RFC 8864]
attribute depend media IDENTICAL-PER-PT [RFC 5583][RFC 8859]
attribute des media CAUTION [RFC 3312][RFC 8859]
attribute dsel media CAUTION [RFC 3108][RFC 8859]
attribute duplication-delay session, media NORMAL [RFC 7197][RFC 8859]
attribute ebuacip media TBD [EBU Tech 3368 - Audio Contribution over IP – Profiles][Felix_Poulin][RFC 8859]
attribute ecan media CAUTION [RFC 3108][RFC 8859]
attribute ecn-capable-rtp media IDENTICAL [RFC 6679][RFC 8859]
attribute eecid media CAUTION [RFC 3108][RFC 8859]
attribute end-of-candidates session, media IDENTICAL [RFC 8840]
attribute etag session, media CAUTION [RFC 2326][RFC 8859]
attribute extmap session, media SPECIAL [RFC 8285][RFC 8859]
attribute extmap-allow-mixed session, media IDENTICAL [RFC 8285]
attribute fec media CAUTION [RFC 3108][RFC 8859]
attribute FEC media NORMAL [RFC-mehta-rmt-flute-sdp-05][RFC 8859]
attribute FEC-declaration session, media TBD [RFC-mehta-rmt-flute-sdp-05][RFC 8859]
attribute FEC-OTI-extension session, media TBD [RFC-mehta-rmt-flute-sdp-05][RFC 8859]
attribute fec-repair-flow media SPECIAL [RFC 6364][RFC 8859]
attribute fec-source-flow media SPECIAL [RFC 6364][RFC 8859]
attribute file-date media, dcsa (msrp) TBD [RFC 5547][RFC 8859][RFC 8873]
attribute file-disposition media, dcsa (msrp) TBD [RFC 5547][RFC 8859][RFC 8873]
attribute file-icon media, dcsa (msrp) TBD [RFC 5547][RFC 8859][RFC 8873]
attribute file-range media, dcsa (msrp) TBD [RFC 5547][RFC 8859][RFC 8873]
attribute file-selector media, dcsa (msrp) TBD [RFC 5547][RFC 8859][RFC 8873]
attribute file-transfer-id media, dcsa (msrp) TBD [RFC 5547][RFC 8859][RFC 8873]
attribute fingerprint session, media TRANSPORT [RFC 8122][RFC 8859]
attribute floorctrl media TBD [RFC 8856][RFC 8859]
attribute floorid media TBD [RFC 8856][RFC 8859]
attribute flute-ch session, media TBD [RFC-mehta-rmt-flute-sdp-05][RFC 8859]
attribute flute-tsi session, media TBD [RFC-mehta-rmt-flute-sdp-05][RFC 8859]
attribute fmtp media, source, dcsa (t140) IDENTICAL-PER-PT [RFC 5576][RFC 8866][RFC 8859][RFC 8865]
attribute framerate media IDENTICAL-PER-PT [RFC 8866][RFC 8859]
attribute framesize media CAUTION [RFC 6064][RFC 8859]
attribute fsel media CAUTION [RFC 3108][RFC 8859]
attribute gc media CAUTION [RFC 3108][RFC 8859]
attribute gpmd media TBD [ITU-T Rec. V.150.1][ITU-T Rec. V.152][Simao_Campos-Neto]
attribute group session NORMAL [RFC 5888][RFC 8859]
attribute h248item session, media SPECIAL [ITU-T H.248.15][RFC 8859]
attribute hlang-recv media, dcsa (t140) NORMAL [RFC 8373][RFC 8865]
attribute hlang-send media, dcsa (t140) NORMAL [RFC 8373][RFC 8865]
attribute icap session, media NORMAL [RFC 7006][RFC 8859]
attribute ice-lite session NORMAL [RFC 8839][RFC 8859]
attribute ice-mismatch media NORMAL [RFC 8839][RFC 8859]
attribute ice-options session NORMAL [RFC 8839][RFC 8859]
attribute ice-pacing session NORMAL [RFC 8839]
attribute ice-pwd session, media TRANSPORT [RFC 8839][RFC 8859]
attribute ice-ufrag session, media TRANSPORT [RFC 8839][RFC 8859]
attribute identity session NORMAL [RFC 8827]
attribute ike-setup session, media IDENTICAL [RFC 6193][RFC 8859]
attribute imageattr media IDENTICAL-PER-PT [RFC 6236][RFC 8859]
attribute inactive session, media, dcsa (t140), dcsa (msrp) NORMAL [RFC 8866][RFC 8859][RFC 8865][RFC 8873]
attribute ipbcp session SPECIAL [ITU-T Recommendation Q.1970, "BICC IP bearer control protocol" (07/2001)][RFC 8859]
attribute isup_usi media CAUTION [RFC 3108][RFC 8859]
attribute key-mgmt session, media IDENTICAL [RFC 4567][RFC 8859]
attribute keywds session NORMAL [RFC 8866][RFC 8859]
attribute label media NORMAL [RFC 4574][RFC 8859]
attribute lang session, media NORMAL [RFC 8866][RFC 8859]
attribute lcfg media SPECIAL [RFC 6871][RFC 8859]
attribute lij media CAUTION [RFC 3108][RFC 8859]
attribute loopback media NORMAL [RFC 6849][RFC 8859]
attribute loopback-mirror media NORMAL [RFC 6849][RFC 8859]
attribute loopback-source media NORMAL [RFC 6849][RFC 8859]
attribute max-message-size media CAUTION [RFC 8841]
attribute max-size media, dcsa (msrp) TBD [RFC 4975][RFC 8859][RFC 8873]
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, media SPECIAL [RFC 3890][RFC 8859]
attribute maxptime media IDENTICAL-PER-PT [RFC 8866][RFC 8859]
attribute mbms-flowid media CAUTION [RFC 6064][RFC 8859]
attribute mbms-mode session, media CAUTION [RFC 6064][RFC 8859]
attribute mbms-repair session, media CAUTION [RFC 6064][RFC 8859]
attribute mediaclk session, media, source NORMAL [RFC 7273][RFC 8859]
attribute mfcap session, media IDENTICAL-PER-PT [RFC 6871][RFC 8859]
attribute mid media NORMAL [RFC 5888][RFC 8859]
attribute mscap session, media INHERIT [RFC 6871][RFC 8859]
attribute msid media NORMAL [RFC 8830]
attribute msrp-cema media, dcsa (msrp) TBD [RFC 6714][RFC 8859][RFC 8873]
attribute mtag session, media CAUTION [RFC 7826][RFC 8859]
attribute multicast-rtcp session, media IDENTICAL [RFC 6128][RFC 8859]
attribute omcap session, media NORMAL [RFC 6871][RFC 8859]
attribute omr-codecs media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Dongwook_Kim][RFC 8859]
attribute omr-m-att media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Dongwook_Kim][RFC 8859]
attribute omr-m-bw media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Dongwook_Kim][RFC 8859]
attribute omr-m-cksum media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Dongwook_Kim][RFC 8859]
attribute omr-s-att media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Dongwook_Kim][RFC 8859]
attribute omr-s-bw media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Dongwook_Kim][RFC 8859]
attribute omr-s-cksum media NORMAL [TS 24.229 v10.7.0 table 7.5.2][Dongwook_Kim][RFC 8859]
attribute onewaySel media CAUTION [RFC 3108][RFC 8859]
attribute orient media NORMAL [RFC 8866][RFC 8859]
attribute orient:landscape media NORMAL [RFC 8866][RFC 8859]
attribute orient:portrait media NORMAL [RFC 8866][RFC 8859]
attribute orient:seascape media NORMAL [RFC 8866][RFC 8859]
attribute path media, dcsa (msrp) TBD [RFC 4975][RFC 8859][RFC 8873]
attribute pcfg media SPECIAL [RFC 5939][RFC 8859]
attribute phone-context session, media TBD [RFC 2848][RFC 8859]
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 [RFC 6284][RFC 8859]
attribute predefined_ROI media IDENTICAL-PER-PT [3GPP TS 26.114 v16.3.0][_3GPP_Specifications_Manager]
attribute previous-ssrc source NORMAL [RFC 5576][RFC 8859]
attribute profileDesc media CAUTION [RFC 3108][RFC 8859]
attribute prtfl media CAUTION [RFC 3108][RFC 8859]
attribute PSCid session NORMAL [Sonia_Compans][TS 183 063 R3 ETSI TISPAN Technical Specification TS 183 063 "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); IMS-based IPTV stage 3 specification"][RFC 8859]
attribute psk-fingerprint session, media IDENTICAL [RFC 6193][RFC 8859]
attribute ptime media IDENTICAL-PER-PT [RFC 8866][RFC 8859]
attribute Q763-INN session, media TBD [RFC 2848][RFC 8859]
attribute Q763-nature session, media TBD [RFC 2848][RFC 8859]
attribute Q763-plan session, media TBD [RFC 2848][RFC 8859]
attribute qos-mech-recv session, media TRANSPORT [RFC 5432][RFC 8859]
attribute qos-mech-send session, media TRANSPORT [RFC 5432][RFC 8859]
attribute qosClass media CAUTION [RFC 3108][RFC 8859]
attribute quality media NORMAL [RFC 8866][RFC 8859]
attribute rams-updates media CAUTION [RFC 6285][RFC 8859]
attribute range session, media CAUTION [RFC 2326][RFC 7826][RFC 8859]
attribute record session, media TBD [RFC 7866][RFC 8859]
attribute recordpref session, media TBD [RFC 7866][RFC 8859]
attribute recvonly session, media, dcsa (t140), dcsa (msrp) NORMAL [RFC 8866][RFC 8859][RFC 8865][RFC 8873]
attribute remote-candidates media TRANSPORT [RFC 8839][RFC 8859]
attribute repair-window media SPECIAL [RFC 6364][RFC 8859]
attribute require session, media TBD [RFC 2848][RFC 8859]
attribute resource media NORMAL [RFC 6787][RFC 8859]
attribute rid media SPECIAL [RFC 8851]
attribute rmcap session, media IDENTICAL-PER-PT [RFC 6871][RFC 8859]
attribute rtcp media TRANSPORT [RFC 3605][RFC 8859]
attribute rtcp-fb media IDENTICAL-PER-PT [RFC 4585][RFC 8859]
attribute rtcp-idms media NORMAL [RFC 7272][RFC 8859]
attribute rtcp-mux media IDENTICAL [RFC 5761][RFC 8035][RFC 8859]
attribute rtcp-mux-only media IDENTICAL [RFC 8858]
attribute rtcp-rgrp session, media IDENTICAL [RFC 8861][RFC 8859]
attribute rtcp-rsize media IDENTICAL [RFC 5506][RFC 8859]
attribute rtcp-unicast media IDENTICAL [RFC 5760][RFC 8859]
attribute rtcp-xr session, media NORMAL [RFC 3611][RFC 8859]
attribute rtpmap media IDENTICAL-PER-PT [RFC 8866][RFC 8859]
attribute rtpred1 media CAUTION [2][RFC 8859]
attribute rtpred2 media CAUTION [2][RFC 8859]
attribute rtsp-ice-d-m session TBD [RFC 7825][RFC 8859]
attribute rtt-mixer media NORMAL [RFC9071, Section 2.3]
attribute sbc media CAUTION [RFC 3108][RFC 8859]
attribute sctp-port media CAUTION [RFC 8841]
attribute sdplang session, media NORMAL [RFC 8866][RFC 8859]
attribute secondary-realm media TRANSPORT [TS 24.229 v10.7.0 table 7.5.2][Dongwook_Kim][RFC 8859]
attribute sendonly session, media, dcsa (t140), dcsa (msrp) NORMAL [RFC 8866][RFC 8859][RFC 8865][RFC 8873]
attribute sendrecv session, media, dcsa (t140), dcsa (msrp) NORMAL [RFC 8866][RFC 8859][RFC 8865][RFC 8873]
attribute sescap session CAUTION [RFC 6871][RFC 8859]
attribute setup session, media, dcsa (msrp) TRANSPORT [RFC 4145][RFC 8859][RFC 8873]
attribute silenceSupp media CAUTION [RFC 3108][RFC 8859]
attribute simulcast media NORMAL [RFC 8853]
attribute source-filter session, media IDENTICAL [RFC 4570][RFC 8859]
attribute sqn session, media NORMAL [RFC 3407][RFC 8859]
attribute SRTPAuthentication media TBD [RFC 5159][RFC 8859]
attribute SRTPROCTxRate media TBD [RFC 5159][RFC 8859]
attribute ssrc media NORMAL [RFC 5576][RFC 8859]
attribute ssrc-group media NORMAL [RFC 5576][RFC 8859]
attribute stc media CAUTION [RFC 3108][RFC 8859]
attribute stkmstream session, media NORMAL [RFC 5159][RFC 8859]
attribute structure media CAUTION [RFC 3108][RFC 8859]
attribute suspended session, media TBD [NENA STA-010.2-2016][Brian_Rosen][RFC 8859]
attribute T38FaxFillBitRemoval media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC 8859]
attribute T38FaxMaxBuffer media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC 8859]
attribute T38FaxMaxDatagram media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC 8859]
attribute T38FaxMaxIFP media TBD [ITU-T Recommendation T.38 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][Simao_Campos-Neto][RFC 8859]
attribute T38FaxRateManagement media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC 8859]
attribute T38FaxTranscodingJBIG media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC 8859]
attribute T38FaxTranscodingMMR media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC 8859]
attribute T38FaxUdpEC media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC 8859]
attribute T38FaxUdpECDepth media TBD [ITU-T Recommendation T.38 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][Simao_Campos-Neto][RFC 8859]
attribute T38FaxUdpFECMaxSpan media TBD [ITU-T Recommendation T.38 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][Simao_Campos-Neto][RFC 8859]
attribute T38FaxVersion media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC 8859]
attribute T38MaxBitRate media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][RFC 8859]
attribute T38ModemType media TBD [ITU-T Recommendation T.38 Annex D, 'SIP/SDP Call Establishment Procedures', September 2010][Simao_Campos-Neto][RFC 8859]
attribute T38VendorInfo media TBD [ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP Call Establishment Procedures', February 2000, July 2005.][RFC 8859]
attribute tcap session, media INHERIT [RFC 5939][RFC 8859]
attribute tls-id media IDENTICAL [RFC 8842]
attribute tool session NORMAL [RFC 8866][RFC 8859]
attribute tra-att session, media NORMAL [http://www.3gpp.org/ftp/Specs/html-info/24229.htm][http://www.3gpp.org/ftp/Specs/html-info/24371.htm]
attribute tra-bw session, media NORMAL [http://www.3gpp.org/ftp/Specs/html-info/24229.htm][http://www.3gpp.org/ftp/Specs/html-info/24371.htm]
attribute tra-contact session, media NORMAL [http://www.3gpp.org/ftp/Specs/html-info/24229.htm][http://www.3gpp.org/ftp/Specs/html-info/24371.htm]
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]
attribute ts-refclk session, media, source NORMAL [RFC 7273][RFC 8859]
attribute type session NORMAL [RFC 8866][RFC 8859]
attribute type:H332 session NORMAL [ITU Recommendation H.332][RFC 8859]
attribute type:broadcast session NORMAL [RFC 8866][RFC 8859]
attribute type:meeting session NORMAL [RFC 8866][RFC 8859]
attribute type:moderated session NORMAL [RFC 8866][RFC 8859]
attribute type:test session NORMAL [RFC 8866][RFC 8859]
attribute uiLayer1_Prot media CAUTION [RFC 3108][RFC 8859]
attribute upcc media CAUTION [RFC 3108][RFC 8859]
attribute userid media TBD [RFC 8856][RFC 8859]
attribute v3cfmtp session, media NORMAL [RFC 10034]
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][Dongwook_Kim][RFC 8859]
attribute vndpar session, media TBD [ITU-T Rec. V.150.1][ITU-T Rec. V.152][Simao_Campos-Neto]
attribute vsel media CAUTION [RFC 3108][RFC 8859]
attribute websocket-uri media CAUTION [RFC 8124]
attribute X-decbyterate media CAUTION [RFC 6064][RFC 8859]
attribute X-initpostdecbufperiod media CAUTION [RFC 6064][RFC 8859]
attribute X-initpredecbufperiod media CAUTION [RFC 6064][RFC 8859]
attribute X-predecbufsize media CAUTION [RFC 6064][RFC 8859]
attribute zrtp-hash media TRANSPORT [RFC 6189][RFC 8859]

content SDP Parameters

Registration Procedure(s)
Specification Required
Expert(s)
Christer Holmberg
Reference
[RFC 4796][RFC 8859]
Available Formats

CSV
Type SDP Name Description Mux Category Reference
content slides Presentation slides NORMAL [RFC 4796][RFC 8859]
content speaker Image from the speaker NORMAL [RFC 4796][RFC 8859]
content sl Sign language NORMAL [RFC 4796][RFC 8859]
content main Main media stream NORMAL [RFC 4796][RFC 8859]
content alt Alternative media stream NORMAL [RFC 4796][RFC 8859]
content g.3gpp.cat Stream associated with the 3GPP Customized Alerting Ringtone (CAT) service NORMAL [3GPP TS 24.182 v11.2.0][Dongwook_Kim][RFC 8859]
content g.3gpp.crs Stream associated with the 3GPP Customized Ringing Signal (CRS) service NORMAL [3GPP TS 24.183 v9.10.0 annex E][Dongwook_Kim][RFC 8859]
content g.3gpp.announcement-no-confirmation Stream associated with video announcement service without user confirmation NORMAL [3GPP TS 24.229]

Semantics for the "group" SDP Attribute

Registration Procedure(s)
Standards Action
Reference
[RFC 5888][RFC 8859]
Available Formats

CSV
Semantics Token Mux Category Reference
Lip Synchronization LS NORMAL [RFC 5888][RFC 8859]
Flow Identification FID NORMAL [RFC 5888][RFC 8859]
Single Reservation flow SRF NORMAL [RFC 3524][RFC 8859]
Alternative Network Address Types ANAT CAUTION [RFC 4091][RFC 8859]
Forward Error Correction (Deprecated) FEC NORMAL [RFC 5956][RFC 8859]
Forward Error Correction FR FEC-FR NORMAL [RFC 5956][RFC 8859]
Composite Session CS NORMAL [RFC-mehta-rmt-flute-sdp-05][RFC 8859]
Decoding Dependency DDP NORMAL [RFC 5583][RFC 8859]
Duplication DUP NORMAL [RFC 7104][RFC 8859]
Splice SPLICE TBD [RFC 8286][RFC 8859]
Media bundling BUNDLE NORMAL [RFC 9143]
CLUE-controlled "m=" line CLUE NORMAL [RFC 8848]
V3C grouping V3C NORMAL [RFC 10034]

"rtcp-fb" Attribute Values

Registration Procedure(s)
First Come First Served with permanent, stable, and publically accessible document.
Reference
[RFC 4585][RFC 8859]
Available Formats

CSV
Value Name Long Name Mux Category Reference
ack Positive acknowledgement IDENTICAL-PER-PT [RFC 4585][RFC 8859]
app Application-defined parameter SPECIAL [RFC 4585][RFC 8859]
ccm Codec Control Commands and Indications IDENTICAL-PER-PT [RFC 5104][RFC 8859]
nack Negative Acknowledgement IDENTICAL-PER-PT [RFC 4585][RFC 8859]
trr-int Minimal receiver report interval IDENTICAL-PER-PT [RFC 4585][RFC 8859]
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 by the endpoint IDENTICAL-PER-PT [3GPP TS 26.114 v16.3.0][Ozgur_Oyman]
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
[RFC 4585][RFC 8859]
Available Formats

CSV
Value Name Long Name Usable with Mux Reference
sli Slice Loss Indication nack IDENTICAL-PER-PT [RFC 4585][RFC 8859]
pli Picture Loss Indication nack IDENTICAL-PER-PT [RFC 4585][RFC 8859]
rpsi Reference Picture Selection Indication ack, nack IDENTICAL-PER-PT [RFC 4585][RFC 8859]
app Application layer feedback ack, nack SPECIAL [RFC 4585][RFC 8859]
rai Rapid Acquisition Indication nack IDENTICAL-PER-PT [RFC 6285][RFC 8859]
tllei Transport-Layer Third-Party Loss Early Indication nack IDENTICAL-PER-PT [RFC 6642][RFC 8859]
pslei Payload-Specific Third-Party Loss Early Indication nack IDENTICAL-PER-PT [RFC 6642][RFC 8859]
ecn Explicit Congestion Notification nack IDENTICAL [RFC 6679][RFC 8859]
ccfb Congestion Control Feedback ack IDENTICAL-PER-PT [RFC 8888]

"depend" SDP Attribute Values

Registration Procedure(s)
Specification Required
Expert(s)
Stephan Wenger
Reference
[RFC 5583][RFC 8859]
Available Formats

CSV
Token Semantics Mux Category Reference
lay Layered decoding dependency IDENTICAL-PER-PT [RFC 5583][RFC 8859]
mdc Multi descriptive decoding dependency IDENTICAL-PER-PT [RFC 5583][RFC 8859]

"cs-correlation" Attribute Values

Registration Procedure(s)
Specification Required
Expert(s)
Bo Burman
Reference
[RFC 7195][RFC 8859]
Available Formats

CSV
Value Description Mux Category Reference
callerid Caller ID TBD [RFC 7195][RFC 8859]
uuie User-User Information Element TBD [RFC 7195][RFC 8859]
dtmf Dual-tone Multi-Frequency TBD [RFC 7195][RFC 8859]
external External TBD [RFC 7195][RFC 8859]

Semantics for the "ssrc-group" SDP Attribute

Registration Procedure(s)
Standards Action
Reference
[RFC 5576][RFC 8859]
Available Formats

CSV
Token Semantics Mux Category Reference
FID Flow Identification NORMAL [RFC 5576][RFC 8859]
FEC Forward Error Correction NORMAL [RFC 5576][RFC 8859]
FEC-FR Forward Error Correction FR NORMAL [RFC 5956][RFC 8859]
DUP Duplication NORMAL [RFC 7104][RFC 8859]

SDP/RTSP key management protocol identifiers

Registration Procedure(s)
Specification Required
Expert(s)
Magnus Westerlund
Reference
[RFC 4567][RFC 8859]
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

CSV
Value Name Long Name Mux Category Reference
mikey Multimedia Internet KEYing IDENTICAL [RFC 4567][RFC 8859]

Codec Control Messages

Registration Procedure(s)
Specification Required
Expert(s)
Stephan Wenger
Reference
[RFC 5104][RFC 8859]
Available Formats

CSV
Value Name Long Name Usable with Mux Reference
fir Full Intra Request Command ccm IDENTICAL-PER-PT [RFC 5104][RFC 8859]
tmmbr Temporary Maximum Media Stream Bit Rate ccm IDENTICAL-PER-PT [RFC 5104][RFC 8859]
tstr Temporal-Spatial Trade-off ccm IDENTICAL-PER-PT [RFC 5104][RFC 8859]
vbcm H.271 video back channel messages ccm IDENTICAL-PER-PT [RFC 5104][RFC 8859]
pause Media Pause/Resume ccm TBD [RFC 7728][RFC 8859]
lrr Layer Refresh Request Command ccm IDENTICAL-PER-PT [RFC 9627]

QoS Mechanism Tokens

Registration Procedure(s)
Specification Required
Expert(s)
Christer Holmberg
Reference
[RFC 5432][RFC 8859]
Available Formats

CSV
QoS Mechanism Mux Category Reference
rsvp TRANSPORT [RFC 5432][RFC 8859]
nsis TRANSPORT [RFC 5432][RFC 8859]

SDP Capability Negotiation Option Tags

Registration Procedure(s)
IETF Review
Reference
[RFC 5939][RFC 8859]
Available Formats

CSV
Option Tag Mux Category Reference
cap-v0 NORMAL [RFC 5939][RFC 8859]
med-v0 NORMAL [RFC 6871][RFC 8859]
bcap-v0 NORMAL [RFC 7006][RFC 8859]
ccap-v0 NORMAL [RFC 7006][RFC 8859]
icap-v0 NORMAL [RFC 7006][RFC 8859]

SDP Capability Negotiation Configuration Parameters Registry

Registration Procedure(s)
IETF Review
Reference
[RFC 5939][RFC 6871]
Available Formats

CSV
Encoding Name Descriptive Name Potential Configuration Definition Actual Configuration Definition Latent Configuration Definition
a Attribute Configuration [RFC 5939] [RFC 5939] [RFC 6871]
b Bandwidth [RFC 7006] [RFC 7006] [RFC 7006]
c Connection Data [RFC 7006] [RFC 7006] [RFC 7006]
i Title [RFC 7006] [RFC 7006] [RFC 7006]
m Media Configuration [RFC 6871] [RFC 6871] [RFC 6871]
mt Media Type [RFC 6871] [RFC 6871] [RFC 6871]
pt Payload Type Number Mapping [RFC 6871] [RFC 6871] [RFC 6871]
t Transport Protocol Configuration [RFC 5939] [RFC 5939] [RFC 6871]

Timestamp Reference Clock Source Parameters

Registration Procedure(s)
Specification Required
Expert(s)
Magnus Westerlund
Reference
[RFC 7273][RFC 8859]
Available Formats

CSV
Name Long Name Mux Category Reference
ntp Network Time Protocol NORMAL [RFC7273, section 4][RFC 8859]
ptp Precision Time Protocol NORMAL [RFC7273, section 4][RFC 8859]
gps Global Positioning System NORMAL [RFC7273, section 4][RFC 8859]
gal Galileo NORMAL [RFC7273, section 4][RFC 8859]
glonass Global Navigation Satellite System NORMAL [RFC7273, section 4][RFC 8859]
local Local Clock NORMAL [RFC7273, section 4][RFC 8859]
private Private Clock NORMAL [RFC7273, section 4][RFC 8859]

Media Clock Source Parameters

Registration Procedure(s)
Specification Required
Expert(s)
Magnus Westerlund
Reference
[RFC 7273][RFC 8859]
Available Formats

CSV
Name Long Name Mux Category Reference
sender Asynchronously Generated Media Clock NORMAL [RFC7273, section 5][RFC 8859]
direct Direct-Referenced Media Clock NORMAL [RFC7273, section 5][RFC 8859]
IEEE1722 IEEE1722 Media Stream Identifier NORMAL [RFC7273, section 5][RFC 8859]

Multiplexing Categories

Registration Procedure(s)
Standards Action
Reference
[RFC 8859]
Available Formats

CSV
Multiplexing Categories Reference
NORMAL [RFC 8859]
CAUTION [RFC 8859]
IDENTICAL [RFC 8859]
TRANSPORT [RFC 8859]
SUM [RFC 8859]
INHERIT [RFC 8859]
IDENTICAL-PER-PT [RFC 8859]
SPECIAL [RFC 8859]
TBD [RFC 8859]

association-usage Name Registry

Registration Procedure(s)
First Come First Served
Reference
[RFC 8841]
Available Formats

CSV
Name Reference Change Controller
webrtc-datachannel [RFC 8841][RFC 8832] IESG

RID Attribute Parameters

Registration Procedure(s)
Specification Required
Expert(s)
Adam Roach
Reference
[RFC 8851]
Available Formats

CSV
RID Parameter Name Reference
pt [RFC 8851]
max-width [RFC 8851]
max-height [RFC 8851]
max-fps [RFC 8851]
max-fs [RFC 8851]
max-br [RFC 8851]
max-pps [RFC 8851]
max-bpp [RFC 8851]
depend [RFC 8851]

Candidate Attribute Extensions

Registration Procedure(s)
Specification Required
Expert(s)
Christer Holmberg
Reference
[RFC 8839]
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
[Dongwook_Kim] Dongwook Kim mailto:dongwook.kim&etsi.org 2026-01-15
[Felix_Poulin] Felix Poulin, EBU-FNS Coordinator mailto:poulin&ebu.ch 2016-11-17
[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 [RFC 2198]