Create a Route name SIPUS_xxxxxxxxxx where xxxxxxxxxx is your SIP.US trunk.
We recommend adding the following 5 Dial Patterns(SIP.US requires 1+10 digit dialing within NANPA and N11/N33 for Emergency and Directory Services and no prefix for International dialing(only country code + number)):
Example of Outbound route Dial Pattern in FreePBX gui:
Prepend + Prefix | Match Pattern
Set the Trunk Sequence for Matched Routes:
Note: The 011 prefix for international calling in the above dial pattern example will be stripped by the pbx before sending.