A user agent client must not send an INVITE with a Replaces header field that attempts to replace an early dialog which was not originated by the target of that INVITE, and should address replacement requests to the SIP Contact URI of the target rather than to an address of record.

Checked 2026-09-16

Vendor
IETF
Product
Session Initiation Protocol
Subsystem
Replaces
Deployment
not restricted
Region
not restricted
Release range
Standards Track
Checked
2026-09-16

Sources

Cite this note

APA

WarmTransfer. (2026, September 16). Call transfer semantics REFER and Replaces: source note xfersem-replaces-uac-rules. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-replaces-uac-rules

BibTeX

@misc{warmtransfer-claim-xfersem-replaces-uac-rules,
  title  = {Call transfer semantics REFER and Replaces: source note xfersem-replaces-uac-rules},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/xfersem-replaces-uac-rules},
  note   = {Source note xfersem-replaces-uac-rules, checked 2026-09-16}
}

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