Hi!
I don't use DISA so I can't tell you if it works properly as far as setting the CID is concerned but assuming it does I can see more than one reason for your problem:
- You set your trunk to "Force Trunk CID".
- Your VoIP provider force you to use a specific CID.
- You are using a technology that doesn't allow you to set the CID (FXO, chan_mobile, etc...).
If your VoIP provider forces you to use a specific CID it might be because they are enforcing you to use a CID they know belong to you or you misconfigured your account with them (VoIP.ms comes to mind for that, if you have an ATA adapter you must provide them with a CID but if you are using a PBX you must blank out that field).
Good luck and have a nice day!
Nick