Three small companies share a CME. They are business partners, so there is no any restriction on internal calls. For outgoing external calls, they want different calling number(caller id) for each company. For example, each company has a main number.
I need to do that on ephone-dn level, but I have no idea about the commands in CME.
We can configure "external mask" on line level with CallManager to resolve this problem. How can I do with CallManager Express?