RFC 5589 requires that the Transferor must know whether or not the transfer was successful, that the Transferee must be able to replace an existing dialog with a new one, and that the Transferor should give the Transfer Target and the Transferee information about the nature and progress of the transfer.

Checked 2026-09-16

Vendor
IETF
Product
Session Initiation Protocol
Subsystem
Transfer requirements
Deployment
not restricted
Region
not restricted
Release range
BCP 149
Checked
2026-09-16

Sources

Cite this note

APA

WarmTransfer. (2026, September 16). Call transfer semantics REFER and Replaces: source note xfersem-transferor-must-know-the-outcome. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-transferor-must-know-the-outcome

BibTeX

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

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