The answer's direction is constrained by the offer's: a sendonly offer must be answered recvonly or inactive, a recvonly offer sendonly or inactive, an inactive offer inactive, and only a sendrecv offer may be answered with any of the four.

field report · Checked 2026-09-15

If a stream is offered as sendonly, the corresponding stream MUST be marked as recvonly or inactive in the answer.
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

Cite this note

APA

WarmTransfer. (2026, September 15). SDP offer answer and codec negotiation: source note sdp-oa-direction-constrains-the-answer. WarmTransfer. https://warmtransfer.net/knowledge/claims/sdp-oa-direction-constrains-the-answer

BibTeX

@misc{warmtransfer-claim-sdp-oa-direction-constrains-the-answer,
  title  = {SDP offer answer and codec negotiation: source note sdp-oa-direction-constrains-the-answer},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sdp-oa-direction-constrains-the-answer},
  note   = {Source note sdp-oa-direction-constrains-the-answer, checked 2026-09-15}
}

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