Source note · SIP OPTIONS pings and trunk keepalives
When the Microsoft SIP proxy receives OPTIONS from an SBC, it looks for a known tenant's SBC FQDN in the Record-Route header first and falls back to the Contact header.
Checked 2026-09-24
- Vendor
- Microsoft
- Product
- Teams Phone Direct Routing
- Subsystem
- SIP proxy
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- SBC connectivity issues — Microsoft · tier 2 current vendor documentation · section 'Overview of the SIP options process', bullet 3
Cite this note
APA
WarmTransfer. (2026, September 24). SIP OPTIONS pings and trunk keepalives: source note sip-options-keepalive-dr-proxy-record-route-contact. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-options-keepalive-dr-proxy-record-route-contact
BibTeX
@misc{warmtransfer-claim-sip-options-keepalive-dr-proxy-record-route-contact,
title = {SIP OPTIONS pings and trunk keepalives: source note sip-options-keepalive-dr-proxy-record-route-contact},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-options-keepalive-dr-proxy-record-route-contact},
note = {Source note sip-options-keepalive-dr-proxy-record-route-contact, checked 2026-09-24}
}