Source note · SDP offer answer and codec negotiation
Media formats must be listed in order of preference with the first being preferred, and the offerer should use the format with the highest preference from the answer, so the codec a call actually uses is chosen by the answerer's ordering and not the offerer's.
field report · Checked 2026-09-15
The media formats in the "m=" line MUST be listed in order of preference, with the first format listed being preferred.
- Vendor
- IETF
- Product
- SIP
- Subsystem
- SDP offer/answer
- Deployment
- not restricted
- Region
- not restricted
- Release range
- RFC 3264
- Status
- field report
- Checked
- 2026-09-15
Sources
- RFC 3264 — An Offer/Answer Model with the Session Description Protocol (SDP) — IETF / RFC Editor · tier 1 standards and regulators · RFC 3264 section 6.1 Unicast Streams
Cite this note
APA
WarmTransfer. (2026, September 15). SDP offer answer and codec negotiation: source note sdp-oa-format-order-is-preference. WarmTransfer. https://warmtransfer.net/knowledge/claims/sdp-oa-format-order-is-preference
BibTeX
@misc{warmtransfer-claim-sdp-oa-format-order-is-preference,
title = {SDP offer answer and codec negotiation: source note sdp-oa-format-order-is-preference},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sdp-oa-format-order-is-preference},
note = {Source note sdp-oa-format-order-is-preference, checked 2026-09-15}
}