In Kamailio's tm module, fr_inv_timer (default 120000 ms) bounds the wait for a final INVITE reply after a provisional reply and by default restarts on each provisional reply.
Checked 2026-10-02
- Vendor
- Kamailio
- Product
- Kamailio
- Subsystem
- tm module
- Deployment
- on-premises
- Region
- not restricted
- Release range
- stable docs as of 2026-10-02
- Checked
- 2026-10-02
Sources
- TM Module — Kamailio project · tier 3 vendor-maintained repositories · Parameters fr_inv_timer and restart_fr_on_each_reply
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting SIP 408 Request Timeout and calls that get no response: source note sip-408-timeout-troubleshooting-kamailio-fr-inv-timer-120s. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-408-timeout-troubleshooting-kamailio-fr-inv-timer-120s
BibTeX
@misc{warmtransfer-claim-sip-408-timeout-troubleshooting-kamailio-fr-inv-timer-120s,
title = {Troubleshooting SIP 408 Request Timeout and calls that get no response: source note sip-408-timeout-troubleshooting-kamailio-fr-inv-timer-120s},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-408-timeout-troubleshooting-kamailio-fr-inv-timer-120s},
note = {Source note sip-408-timeout-troubleshooting-kamailio-fr-inv-timer-120s, checked 2026-10-02}
}