There is a Caller ID issue happened recently in our CM 4 system.
Previously, all our outgoing calls have been configured to send out the caller ID of company's primary phone number.
But now it shows "unknown number" on far end. I called our CO line provider, but no changes had been made on their end. (Not sure if any setting been changed in our CM)
The funny thing is, when I set a call forward all to my cell phone, the caller ID appears again. (caller ID only works when call forward is activating)
I can not figure out how this happens.
Can some one teach me how to make a troubleshoot?