Source note · Call transfer semantics REFER and Replaces

The Refer-To header field carries the URL being referenced and appears only in a REFER request, and RFC 3515 states that the Contact header field is part of the Route and Record-Route mechanism and is not available to indicate the target of the reference.

Checked 2026-09-16

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

Sources

RFC 3515 — The Session Initiation Protocol (SIP) Refer Method — IETF / RFC Editor · tier 1 standards and regulators · RFC 3515 section 2.1 The Refer-To Header Field

Cite this note

APA

WarmTransfer. (2026, September 16). Call transfer semantics REFER and Replaces: source note xfersem-contact-is-not-the-reference-target. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-contact-is-not-the-reference-target

BibTeX

@misc{warmtransfer-claim-xfersem-contact-is-not-the-reference-target,
  title  = {Call transfer semantics REFER and Replaces: source note xfersem-contact-is-not-the-reference-target},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/xfersem-contact-is-not-the-reference-target},
  note   = {Source note xfersem-contact-is-not-the-reference-target, checked 2026-09-16}
}

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