Source note · Troubleshooting calls that drop on hold or transfer
Microsoft says media bypass and Local Media Optimization require several reinvites by design, and that a reinvite from the SBC arriving at the SIP proxy in the wrong order or at the wrong time creates a race condition that lengthens negotiation and delays audio.
Checked 2026-09-30
- Vendor
- Microsoft
- Product
- Teams Phone Direct Routing
- Subsystem
- sip-dialog
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-30
- Checked
- 2026-09-30
Sources
- Issues that affect inbound Direct Routing calls — Microsoft · tier 2 current vendor documentation · Delay when answering PSTN calls in Teams
Cite this note
APA
WarmTransfer. (2026, September 30). Troubleshooting calls that drop on hold or transfer: source note sip-reinvite-call-drops-dr-reinvite-race. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-reinvite-call-drops-dr-reinvite-race
BibTeX
@misc{warmtransfer-claim-sip-reinvite-call-drops-dr-reinvite-race,
title = {Troubleshooting calls that drop on hold or transfer: source note sip-reinvite-call-drops-dr-reinvite-race},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-reinvite-call-drops-dr-reinvite-race},
note = {Source note sip-reinvite-call-drops-dr-reinvite-race, checked 2026-09-30}
}