Source note · Call transfer semantics REFER and Replaces
In an attended transfer the Transferor places the Transferee on hold, establishes a call with the Transfer Target to alert them to the impending transfer, places the Target on hold, and then transfers using an escaped Replaces header field inside the Refer-To header.
Checked 2026-09-16
The Transferor places the Transferee on hold, establishes a call with the Transfer Target to alert them to the impending transfer, places the target on hold, then proceeds with transfer using an escaped Replaces header field in the Refer-To header.
- Vendor
- IETF
- Product
- Session Initiation Protocol
- Subsystem
- Attended transfer
- 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 7.3 Attended Transfer, opening paragraph
Cite this note
APA
WarmTransfer. (2026, September 16). Call transfer semantics REFER and Replaces: source note xfersem-attended-transfer-is-hold-consult-hold-refer. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-attended-transfer-is-hold-consult-hold-refer
BibTeX
@misc{warmtransfer-claim-xfersem-attended-transfer-is-hold-consult-hold-refer,
title = {Call transfer semantics REFER and Replaces: source note xfersem-attended-transfer-is-hold-consult-hold-refer},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/xfersem-attended-transfer-is-hold-consult-hold-refer},
note = {Source note xfersem-attended-transfer-is-hold-consult-hold-refer, checked 2026-09-16}
}