Derived trunk in same tenant where the parent trunk is registered


I'd like to find out if it should be possible to use derived trunks in the same tenant in which the parent trunk is configured.


My configuration looks like the below:

  • Parent trunk `` is configured in TAC and connected to a working SBC. The trunk is showing healthy with no issues reported.
  • Base domain and subdomains have been registered in M365, in the same tenant:
    • ``
    • ``
    • ``

I am able to create voice routes which use `` but when I try to create voice routes using the derived trunk, e.g.:



New-CsOnlineVoiceRoute -Identity Route1 -OnlinePstnUsages @{add="Account1Record"} -OnlinePstnGatewayList @{add=""} -NumberPattern ".*"



It fails with the error:

New-CsOnlineVoiceRoute: Cannot find specified Gateway "".


Is this because I have some incorrect configuration, or is using derived trunks in this manner not supported?

1 Reply

Hi @SimranDhillon ,

I'm not sure if it works also in the same Tenant.

But the derived trunk setup works for different tenants. Look at the Microsoft learn article describing a hosted SBC model for a carrier setup.


Best regards,