Source note · Call transfer semantics REFER and Replaces
Every NOTIFY reporting a refer must carry an Event header field with the value refer and a message/sipfrag body that begins with a SIP Response Status-Line whose response class indicates the status of the referred action, and the refer event package does not support state deltas so each body is a complete statement of status.
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 sections 2.4.4 and 2.4.5
Cite this note
APA
WarmTransfer. (2026, September 16). Call transfer semantics REFER and Replaces: source note xfersem-refer-notify-carries-a-sipfrag-status-line. WarmTransfer. https://warmtransfer.net/knowledge/claims/xfersem-refer-notify-carries-a-sipfrag-status-line
BibTeX
@misc{warmtransfer-claim-xfersem-refer-notify-carries-a-sipfrag-status-line,
title = {Call transfer semantics REFER and Replaces: source note xfersem-refer-notify-carries-a-sipfrag-status-line},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/xfersem-refer-notify-carries-a-sipfrag-status-line},
note = {Source note xfersem-refer-notify-carries-a-sipfrag-status-line, checked 2026-09-16}
}