RFC 6337 cautions that if media is already flowing using a re-INVITE's new offer, the UA should send a 2xx instead of 488 and then correct parameters with UPDATE or terminate.

Checked 2026-09-25

Vendor
IETF
Product
SIP
Subsystem
offer rejection
Deployment
any
Region
not restricted
Release range
RFC 6337
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP 488 and codec negotiation failures: source note sip-488-codec-failures-reinvite-media-caveat. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-488-codec-failures-reinvite-media-caveat

BibTeX

@misc{warmtransfer-claim-sip-488-codec-failures-reinvite-media-caveat,
  title  = {SIP 488 and codec negotiation failures: source note sip-488-codec-failures-reinvite-media-caveat},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-488-codec-failures-reinvite-media-caveat},
  note   = {Source note sip-488-codec-failures-reinvite-media-caveat, checked 2026-09-25}
}

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