Source note · Troubleshooting calls that drop on hold or transfer
When a media bypass call is transferred to a Skype for Business, Teams Web or Teams VDI client, Direct Routing inserts a Media Processor and starts an ICE restart by changing ice-pwd and ice-ufrag and offering new candidates in a reinvite; the SBC must support ICE restarts.
Checked 2026-09-30
- Vendor
- Microsoft
- Product
- Teams Phone Direct Routing
- Subsystem
- media-bypass
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-30
- Checked
- 2026-09-30
Sources
- Teams Phone System Direct Routing: SIP protocol — Microsoft · tier 2 current vendor documentation · ICE Restart: Media bypass call transferred to an endpoint that doesn't support media bypass
Cite this note
APA
WarmTransfer. (2026, September 30). Troubleshooting calls that drop on hold or transfer: source note sip-reinvite-call-drops-dr-ice-restart-on-transfer. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-reinvite-call-drops-dr-ice-restart-on-transfer
BibTeX
@misc{warmtransfer-claim-sip-reinvite-call-drops-dr-ice-restart-on-transfer,
title = {Troubleshooting calls that drop on hold or transfer: source note sip-reinvite-call-drops-dr-ice-restart-on-transfer},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-reinvite-call-drops-dr-ice-restart-on-transfer},
note = {Source note sip-reinvite-call-drops-dr-ice-restart-on-transfer, checked 2026-09-30}
}