A 408 that the caller's own UA or proxy reports after a run of retransmitted INVITEs with no response in the trace was most likely generated locally on transaction timeout, so the trace point where responses stop, not the 408, locates the fault.
inferred · Checked 2026-10-02
- Vendor
- not restricted
- Product
- not restricted
- Subsystem
- troubleshooting method
- Deployment
- any
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Status
- inferred
- Checked
- 2026-10-02
Sources
- RFC 3261 — SIP: Session Initiation Protocol — IETF / RFC Editor · tier 1 standards and regulators · Section 8.1.3.1 (timeout treated as 408); see also Kamailio tm fr_timer
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-inf-local-408-no-packet. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-408-timeout-troubleshooting-inf-local-408-no-packet
BibTeX
@misc{warmtransfer-claim-sip-408-timeout-troubleshooting-inf-local-408-no-packet,
title = {Troubleshooting SIP 408 Request Timeout and calls that get no response: source note sip-408-timeout-troubleshooting-inf-local-408-no-packet},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-408-timeout-troubleshooting-inf-local-408-no-packet},
note = {Source note sip-408-timeout-troubleshooting-inf-local-408-no-packet, checked 2026-10-02}
}