A REFER request implicitly establishes a subscription to the refer event, creates a dialog and so must contain a single Contact header field value, may be placed outside the scope of a dialog created with an INVITE, and when sent inside an existing dialog must follow that dialog's Route and Record-Route logic.

Checked 2026-09-16 · superseded by xfersem-refer-must-be-out-of-dialog-with-gruu

Vendor
IETF
Product
Session Initiation Protocol
Subsystem
REFER
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-refer-creates-a-dialog-and-a-subscription. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-refer-creates-a-dialog-and-a-subscription

BibTeX

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

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