MS Teams -> anynode SBC -> CUCM -> PSTN

[smccloud1]

Hello,

I am trying to configure one of our lab Teams users with Direct Routing using an anynode SBC and our production CUCM.  I have been able to get calls from a PSTN device to the Teams user.  However, every time I try to call from the Teams user to a PSTN number, I get a SIP/2.0 500 Internal Server error with a reason of Q.850;cause=100.  Looking at RTMT I don't see any trace of the call coming in so all my debugging has been using Wireshark so far.

Any info you need please let me know.

[Lokesh Kumar Lal]

I would start with the CUCM SDL logs. Try searching for the specific call ID.

Also good to capture call control /protocol debugs on the terminating PSTN gateway

[Ritesh Desai]

Hi @smccloud1 

Make sure your SBC model is in list of Microsoft certified SBC.

https://docs.microsoft.com/en-us/MicrosoftTeams/direct-routing-border-controllers

[smccloud1]

@Ritesh Desai The anynode SBC is on the supported list.

@Lokesh Kumar Lal Sanitized SDL log is attached.  I'm wondering if part of the issue is the call coming from Teams doesn't have the same number as actually assigned to the user as its source.

[Mahmoud Belhaj]

You should have public certificate by trusted issuer listed by microsoft