Source note · CUCM to Teams Phone migration
In split-tunnel VPN scenarios where the Teams client is detected as external but can still reach the internal interface of the Direct Routing SBC, Microsoft signals the external location to the SBC, which can cause prolonged call setup and in some cases no audio on inbound PSTN calls; the page says VPN administrators must block access between remote VPN users and the SBC internal interface.
Checked 2026-09-16
- Vendor
- Microsoft
- Product
- Teams Phone Direct Routing
- Subsystem
- Local Media Optimization
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-16
- Checked
- 2026-09-16
Sources
- Configure Local Media Optimization for Direct Routing — Microsoft · tier 2 current vendor documentation · Configure the user and the SBC sites > Note on split-tunnel VPN
Cite this note
APA
WarmTransfer. (2026, September 16). CUCM to Teams Phone migration: source note cucm-to-teams-phone-lmo-split-tunnel-vpn-hazard. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-to-teams-phone-lmo-split-tunnel-vpn-hazard
BibTeX
@misc{warmtransfer-claim-cucm-to-teams-phone-lmo-split-tunnel-vpn-hazard,
title = {CUCM to Teams Phone migration: source note cucm-to-teams-phone-lmo-split-tunnel-vpn-hazard},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cucm-to-teams-phone-lmo-split-tunnel-vpn-hazard},
note = {Source note cucm-to-teams-phone-lmo-split-tunnel-vpn-hazard, checked 2026-09-16}
}