I have an education Tenant with Direct Routing enabled. Connecting to two different SBC, in two different networks.
When a user is logged on with a Polycom phone and receives a call - the call is answered and drops in 15 seconds - without any audio. All other devices work.
In Teams Reports the call - however with SipFinal Code 410, subcode: 531004, code phrase:'IceConnectivityChecksFailed'
Testing done to date:
Same phone on different tenant is fine - rules out phone?
Same Tenant different SBC- rules out SBC? - the second sbc we use is used by multiple clients without issue.
When comparing phone logs for working tenant and failing - the only major item i notice is almost NO candidates being offered by MS when audio does not work.