Source note · SIP trunk redundancy and failover design
Failover triggers are not uniform across hops: RFC 3263 fails over on 503, transport failure or timeout; Teams defaults to 408/503/504 plus a 10-second timer; Twilio origination uses a 4-second no-response rule with an exclusion list; CUCM OPTIONS ping treats 408/503 as down. End-to-end failover time therefore has to be measured per hop rather than assumed.
inferred · Checked 2026-09-25
- Vendor
- multi-vendor
- Product
- SIP trunking
- Subsystem
- failover design
- Deployment
- multi-tenant, on-premises
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Status
- inferred
- Checked
- 2026-09-25
Sources
- Set-CsOnlinePSTNGateway (MicrosoftTeams) — Microsoft · tier 2 current vendor documentation · Parameters -FailoverResponseCodes and -FailoverTimeSeconds, read against the other sources listed in corroborated_by
Cite this note
APA
WarmTransfer. (2026, September 25). SIP trunk redundancy and failover design: source note sip-trunk-redundancy-design-inf-failover-semantics-differ. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-trunk-redundancy-design-inf-failover-semantics-differ
BibTeX
@misc{warmtransfer-claim-sip-trunk-redundancy-design-inf-failover-semantics-differ,
title = {SIP trunk redundancy and failover design: source note sip-trunk-redundancy-design-inf-failover-semantics-differ},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-trunk-redundancy-design-inf-failover-semantics-differ},
note = {Source note sip-trunk-redundancy-design-inf-failover-semantics-differ, checked 2026-09-25}
}