Source note · Troubleshooting calls that drop on hold or transfer
In the basic transfer flow the Transferor first places the Transferee on hold with a re-INVITE and then sends a REFER naming the Transfer Target.
Checked 2026-09-30
- Vendor
- IETF
- Product
- SIP
- Subsystem
- call-transfer
- Deployment
- any
- Region
- not restricted
- Release range
- RFC as published; BCP 149
- Checked
- 2026-09-30
Sources
- RFC 5589 — Session Initiation Protocol (SIP) Call Control - Transfer — IETF / RFC Editor · tier 1 standards and regulators · Section 6 (Basic Transfer)
Cite this note
APA
WarmTransfer. (2026, September 30). Troubleshooting calls that drop on hold or transfer: source note sip-reinvite-call-drops-transfer-hold-then-refer. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-reinvite-call-drops-transfer-hold-then-refer
BibTeX
@misc{warmtransfer-claim-sip-reinvite-call-drops-transfer-hold-then-refer,
title = {Troubleshooting calls that drop on hold or transfer: source note sip-reinvite-call-drops-transfer-hold-then-refer},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-reinvite-call-drops-transfer-hold-then-refer},
note = {Source note sip-reinvite-call-drops-transfer-hold-then-refer, checked 2026-09-30}
}