Source note · Call transfer semantics REFER and Replaces
A user agent accepting a well-formed REFER should request approval from the user to proceed, which may be satisfied interactively or from configured policy, and may decline the request if that approval is immediately denied; RFC 3515 also says a user agent not capable of accessing non-SIP URIs should not accept REFER requests to them.
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 2.4.2
Cite this note
APA
WarmTransfer. (2026, September 16). Call transfer semantics REFER and Replaces: source note xfersem-refer-approval-may-be-sought. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-refer-approval-may-be-sought
BibTeX
@misc{warmtransfer-claim-xfersem-refer-approval-may-be-sought,
title = {Call transfer semantics REFER and Replaces: source note xfersem-refer-approval-may-be-sought},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/xfersem-refer-approval-may-be-sought},
note = {Source note xfersem-refer-approval-may-be-sought, checked 2026-09-16}
}