pbxnsip – Representing the Source
The system differentiates between the following two numbers when presenting a number on the trunk.
1) Display number: This number is the number that the user should see on the display of the phone. In the case of a redirected call, this number would be the original caller-ID that the system sees on the incoming call.
2) Network number: This number is the number that the provider wants to see for billing purposes.
Over the last couple of years, different providers have developed different ways to represent these two numbers.
