Source note · Call transfer semantics REFER and Replaces

The media negotiated between the Transferee and the Transfer Target is not affected by the media negotiated between the Transferor and the Transferee: the INVITE the Transferee issues carries the same session description it would have carried had the Transferee initiated that call on its own, and the REFER does not alter the media streams between the Transferor and the Transferee.

Checked 2026-09-16

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

Sources

RFC 5589 — Session Initiation Protocol (SIP) Call Control - Transfer — IETF / RFC Editor · tier 1 standards and regulators · RFC 5589 section 5, second paragraph

Cite this note

APA

WarmTransfer. (2026, September 16). Call transfer semantics REFER and Replaces: source note xfersem-media-is-renegotiated-from-scratch. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-media-is-renegotiated-from-scratch

BibTeX

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

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