Outbound PSTN Dialing from Teams Meeting for Users with AudioConferencing License

Making and outbound PSTN calls using Direct Routing (DR) from a Teams meeting can follow two different paths:

• If the Meeting Organizer (MO) does NOT have Audio Conferencing, then adding a Person to the call via phone number will work (and can be done by anyone on the call, subject to the settings for the meeting). The call will go out over DR and the Calller ID (CLID) of the call will be the Meeting Organizer’s CLID (as sent by the PBX)
  

• If the Meeting Organizer (MO) HAS Audio Conferencing, then adding a PSTN fails because the outbound call is made in a way that is not accepted by the DR infrastructure. This can be overcome but it requires more complicated configuration as described below.

The setup in the context of Audio Conferencing has several elements. At a high level:

1. Audio Conferencing Voice Routing Policy needs to be created.
   

2. That Policy needs to be assigned to any Teams user that may need to add a PSTN call to a meeting that they organize.

3. The outbound call resulting from adding a PSTN number to the meeting is sent with the CLID of the Default Service Number for the bridge.
   

   1. This number needs to be associated to a SIP user on the PBX so that the ConnecttoTeams B2BUA can recognize the outbound call as valid.
      

   2. The most expedient way to do this is to configure a Teams user specifically for this purpose (possibly a resource account or other “free” account), with a SIP credential and assigned that special number.

In detail, below are the steps. This requires PowerShell and the cooperation of the tenant admin.

1. Set up the Policy

If you don't have the teams powershell configured then you may need to execute these preliminary commands

This is the powershell command to create the policy:

Note

the PSTNUsage may vary depending on which SBC gateway(s) you have selected. The value TM_PBX_Unrestricted as shown here is for the US East gateway. It will need to be adjusted to match your situation if that is not one of your Direct Routes . Contact support for assistance.

2. Assign to user

Each user with AudioConferencing (such as user@domain shown here) will need to be assigned that policy:

3. Determine default service number:

This command will display the Default Service Number for your tenant:

4. Set up a AA resource account

In Teams Admin Center > Voice > Resource Accounts, add new one such as this:

5. Assign that resource account a Teams Phone Resource Account

Do this in M365 Admin Center. These are free licenses.

6. Create a SIP extension on the PBX to use for these outbound calls

You’ll want to set up the user to have outbound calling; this extension will be used for all PSTN calls from the Teams Meeting (where Audio Conferencing is used).

7. Configure the AA resource account with that SIP extension in the ConnecttoTeams Enterprise Portal

You need to build the user so that it has the default service number (as determined in step 3) as their Teams number. The number or ext on the PBX doesn’t matter.

CallerID should probably be set in your PBX to reflect the customer's main number or something similar.