Few points regarding Location based routing debug in Teams. A user can not call out and Teams shows error message:
"Get Outbound Direct routing - no trunk config found by LBR selection criteria."
in Usage reports, as well as in client logs (Ctrl-Shift-Alt-1 to generate logs in Teams client):
"terminatedReason": 72,
"ccCode": 403,
"ccSubcode": 510546,
"phrase": "Get Outbound Direct routing - no trunk config found by LBR selection criteria."
One of the possible reasons is that user has no Calling policy "AllowCallsPreventTollBypass"
The prerequisites for LBR:
Voice policy has PSTN usage pointing to routes to SBC with LBR enabled.
User connects from LAN segment that is known and attached to a network location
External public IP is in trusted list (if protected by Zscaler or something like that all Zscaler ranges must be in the trusted IP list, if no prox, then outgoing firewall IP must be included)
SBC is attached to the LBR location.
User has calling policy to prevent toll