Source note · Call transfer semantics REFER and Replaces
A user agent that fully supports RFC 5589 transfer supports REFER and Replaces in addition to RFC 3261 and supports the Target-Dialog header field, and participants in a basic transfer should advertise REFER and NOTIFY in Allow header fields on INVITE, 200 OK and OPTIONS and advertise Target-Dialog in Supported.
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
- RFC 5589 — Session Initiation Protocol (SIP) Call Control - Transfer — IETF / RFC Editor · tier 1 standards and regulators · RFC 5589 section 1 Overview and section 6 paragraph 3
Cite this note
APA
WarmTransfer. (2026, September 16). Call transfer semantics REFER and Replaces: source note xfersem-capability-advertisement-for-transfer. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-capability-advertisement-for-transfer
BibTeX
@misc{warmtransfer-claim-xfersem-capability-advertisement-for-transfer,
title = {Call transfer semantics REFER and Replaces: source note xfersem-capability-advertisement-for-transfer},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/xfersem-capability-advertisement-for-transfer},
note = {Source note xfersem-capability-advertisement-for-transfer, checked 2026-09-16}
}