Source note · SIP trunk capacity and concurrent call planning
When two or more SBCs in a Direct Routing route are healthy and of equal priority, Direct Routing distributes calls between them with a Fisher-Yates shuffle; SBC health is judged from SIP OPTIONS received in the last three minutes.
Checked 2026-09-24
- Vendor
- Microsoft
- Product
- Teams Phone Direct Routing
- Subsystem
- SBC selection
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- Monitor Direct Routing — Microsoft · tier 2 current vendor documentation · Section 'Monitoring availability of Session Border Controllers using Session Initiation Protocol (SIP) options messages'
Cite this note
APA
WarmTransfer. (2026, September 24). SIP trunk capacity and concurrent call planning: source note sip-trunk-capacity-planning-ms-sbc-shuffle. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-trunk-capacity-planning-ms-sbc-shuffle
BibTeX
@misc{warmtransfer-claim-sip-trunk-capacity-planning-ms-sbc-shuffle,
title = {SIP trunk capacity and concurrent call planning: source note sip-trunk-capacity-planning-ms-sbc-shuffle},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-trunk-capacity-planning-ms-sbc-shuffle},
note = {Source note sip-trunk-capacity-planning-ms-sbc-shuffle, checked 2026-09-24}
}