RFC 6337 acknowledges that its recommended behaviour for offers in response to offerless INVITEs is not always achievable, for example in some interworking scenarios.

Checked 2026-09-25

The behavior above is recommended, but it is not always achievable, for example, in some interworking scenarios.
Vendor
IETF
Product
SIP
Subsystem
offer-answer
Deployment
any
Region
not restricted
Release range
RFC 6337 (Informational)
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP early offer and delayed offer: source note sip-early-delayed-offer-rfc6337-interworking-limit. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-early-delayed-offer-rfc6337-interworking-limit

BibTeX

@misc{warmtransfer-claim-sip-early-delayed-offer-rfc6337-interworking-limit,
  title  = {SIP early offer and delayed offer: source note sip-early-delayed-offer-rfc6337-interworking-limit},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-early-delayed-offer-rfc6337-interworking-limit},
  note   = {Source note sip-early-delayed-offer-rfc6337-interworking-limit, checked 2026-09-25}
}

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