CID Num Alias Call Matching Failover

If I put a DID number in the extension under CID num alias, calls that were reported busy from the first trunk would not fail over to the second. I set the outgoing routes callerid match field to match that of the DID set in CID num alias. This routed the call successfully to the first trunk, but if a failure happened, it would act as though a second trunk was not listed in the outbound route, when 4 were already selected. Clearing the CID num alias in extensions and changing the match callerid field in outbound routes to the extension number, allowed failover to work correctly. I would label this a workaround, but not allowing the desired results.