Source note · Call transfer semantics REFER and Replaces
RFC 5589 names 4 further roles used to describe transfer scenarios rather than the transfer itself: the Originator places the first INVITE, a Facilitator connects the Originator to the Recipient on the Originator's behalf, a Screener receives a call intended for the Recipient and transfers it on if appropriate, and the Recipient is the party the Originator is ultimately connected to.
Checked 2026-09-16
- Vendor
- IETF
- Product
- Session Initiation Protocol
- Subsystem
- Transfer roles
- 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 2 Actors and Roles, second list
Cite this note
APA
WarmTransfer. (2026, September 16). Call transfer semantics REFER and Replaces: source note xfersem-four-scenario-roles. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-four-scenario-roles
BibTeX
@misc{warmtransfer-claim-xfersem-four-scenario-roles,
title = {Call transfer semantics REFER and Replaces: source note xfersem-four-scenario-roles},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/xfersem-four-scenario-roles},
note = {Source note xfersem-four-scenario-roles, checked 2026-09-16}
}