V.3 SDP Examples on DBI Signaling Capability

26.1143GPPIP Multimedia Subsystem (IMS)Media handling and interactionMultimedia telephonyRelease 18TS

Table V.3.1 demonstrates an example SDP offer with Delay Budget Information (DBI) signalling capability for speech, based on the procedures specified in clause 6.2.8. The offer for DBI is indicated in the last line. The use of RTCP feedback messages carrying ‘DBI’ is negotiated with the ‘3gpp-delay-budget’ parameter.

Table V.3.1: Example SDP offer with DBI

SDP offer

m=audio 49152 RTP/AVP 97 98 99 100 101 b=AS:42 b=RS:0 b=RR:2000 a=tcap:1 RTP/AVPF a=pcfg:1 t=1 a=rtpmap:97 EVS/16000/1 a=fmtp:97 br=5.9-24.4; bw=nb-swb; max-red=220 a=rtpmap:98 AMR-WB/16000/1 a=fmtp:98 mode-change-capability=2; max-red=220 a=rtpmap:99 AMR-WB/16000/1 a=fmtp:99 mode-change-capability=2; max-red=220; octet-align=1 a=rtpmap:100 AMR/8000/1 a=fmtp:100 mode-change-capability=2; max-red=220 a=rtpmap:101 AMR/8000/1 a=fmtp:101 mode-change-capability=2; max-red=220; octet-align=1 a=ptime:20 a=maxptime:240 a=rtcp-fb:* 3gpp-delay-budget

An example SDP answer is shown in Table V.3.2, where the DBI signalling capability is also supported by the answerer, as indicated by the last line.

Table V.3.2: Example SDP answer with DBI

SDP answer

m=audio 49152 RTP/AVPF 97 b=AS:30 b=RS:0 b=RR:2000 a=acfg:1 t=1 a=rtpmap:97 EVS/16000/1 a=fmtp:97 br=5.9-13.2; bw=nb-wb; mode-set=0,1,2; max-red=220 a=ptime:20 a=maxptime:240 a=rtcp-fb:* 3gpp-delay-budget

Annex W (Normative):
Coverage and Handoff Enhancements using Multimedia Error Robustness (CHEM)