Trunk does not support DID -> How to select inbound route?

Hi Everybody,

i’m using FreePBX with 4 Trunks, one is a Sipgate-Trunking account with several numbers, the others are normal sipgate-trunks with just one number assigned.
The Trunking account just shows the DID so i can set inbound routes for it. The other trunks don’t so they all go to the default-route.
How can i select a specific inbound route for a trunk without DID? Is there any possibility?

Thanks for your help!

How to get the DID of a SIP trunk when the provider doesn’t send it (and why some incoming SIP calls fail):

http://www.freepbx.org/support/documentation/howtos/how-to-get-the-did-of-a-sip-trunk-when-the-provider-doesnt-send-it-and-