Source note · Call transfer semantics REFER and Replaces
REFER is the only mechanism that can create a subscription to the refer event, and a SUBSCRIBE request for event refer received for a subscription that does not already exist must be rejected with a 403.
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 2.4.4
Cite this note
APA
WarmTransfer. (2026, September 16). Call transfer semantics REFER and Replaces: source note xfersem-refer-is-the-only-way-into-the-package. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-refer-is-the-only-way-into-the-package
BibTeX
@misc{warmtransfer-claim-xfersem-refer-is-the-only-way-into-the-package,
title = {Call transfer semantics REFER and Replaces: source note xfersem-refer-is-the-only-way-into-the-package},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/xfersem-refer-is-the-only-way-into-the-package},
note = {Source note xfersem-refer-is-the-only-way-into-the-package, checked 2026-09-16}
}