I have a user with ip phone registered to call manager 9.
the user's DN's external mask is a invalid 800 number. When he calls a third-party's call center, he can choose the option 1, then 1, then 2, and at the forth level, he choose option 4 then the call is droped.
We spend a lot of hours on the CUCM traces and gateway debugs, found nothing wrong. DTMF relay is good.
Then after we changed the DN's external mask to a valid phone number, it works:)
So do you think this is the third-party's call center's issue, or just the Telco doesn't like the invalid external mask/ calling id?