Source note · Troubleshooting calls that drop on hold or transfer
SIP session timers are a keepalive: user agents send periodic re-INVITE or UPDATE requests, called session refresh requests, to keep the session alive.
Checked 2026-09-30
- Vendor
- IETF
- Product
- SIP
- Subsystem
- session-timer
- Deployment
- any
- Region
- not restricted
- Release range
- RFC as published
- Checked
- 2026-09-30
Sources
- RFC 4028: Session Timers in the Session Initiation Protocol (SIP) — IETF / RFC Editor · tier 1 standards and regulators · Section 1 (Introduction)
Cite this note
APA
WarmTransfer. (2026, September 30). Troubleshooting calls that drop on hold or transfer: source note sip-reinvite-call-drops-session-timer-purpose. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-reinvite-call-drops-session-timer-purpose
BibTeX
@misc{warmtransfer-claim-sip-reinvite-call-drops-session-timer-purpose,
title = {Troubleshooting calls that drop on hold or transfer: source note sip-reinvite-call-drops-session-timer-purpose},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-reinvite-call-drops-session-timer-purpose},
note = {Source note sip-reinvite-call-drops-session-timer-purpose, checked 2026-09-30}
}