Since you are setting different Domain you will need to create two SIP Trunks one for each provider following should get you going in the right direction. Anywhere you NXX-NXX-XXXX substitute correct number for that carrier. The Voice Grouped trunk is where you create allowed and rejected calls or set priority on trunk by setting a cost to make one trunk preferred over another for those calls. In the example I made carrierA the preferred carrier for local outbound and carrier the preferred carrier for outbound toll free calls, both trunks block outbound 976 calls. On the voice user I set CarrierA inbound number as the main user number and CarrierB inbound as a DID.
Voice Trunk T01 type SIP
match dnis , replace ani NXX-NXX-XXXX
!match line overrides outbound caller id to match that carriers outbound number
Sip-server primary carrierasbc.abc.com
Registrar primary carrierasbc.abc.com
domain abc.com
Register NXXNXXXXXX auth-name "name" password "pass"
authentication username "name" password "pass"
Voice Trunk T02 type SIP
match dnis , replace ani NXX-NXX-XXXX
!match line overrides outbound caller id to match that carriers outbound number
Sip-server primary Carriberb.xyz.com
Registrar primary Carriberb.xyz.com
domain xyz.com
Register NXXNXXXXXX auth-name "name" password "pass"
authentication username "name" password "pass"
Voice Grouped Trunk CarrierA
trunk T01
accept NXX-NXX-XXXX cost 10
accept 1-8XX-NXX-XXXX cost 100
reject 1-976-NXX-XXXX
!This is where you set the trunk to accept or deny specific outbound calls
Voice Grouped Trunk CarrierB
trunk T02
accept NXX-NXX-XXXX cost 100
accept 1-8XX-NXX-XXXX cost 10
reject 1-976-NXX-XXXX
!This is where you set the trunk to accept or deny specific outbound calls by setting a higher cost it make the other trunk preffered
Voice user NXXNXXXXXX
!Number in voice user line is inbound number for main carrier
connect fxs 0/1
did NXXNXXXXXX
!DID number is is number of carrier B for inbound calls
John Wable
