My 2811 does not dial area codes beginning with 0. This happened after I upgraded the IOS. I rolled back to the previous version, the same problem is still there. I tried a third version, still the same problem. I did not have any configuration changes during the upgrade.
It works when I modify the translation rule to have a non-zero prefix and dial the non-zero code. But the users do not want to dial an addition non-zero prefix to the called number.
Call-forward all to zero-prefixed numbers are working, but 'busy' and 'noan' are not.
The problem seems to be between ip phones and CME. Debug shows the CME does not find a dial-peer, but it sends out busy signal to the phone after it collects the first 2 digits. All later digits are ignored.
Any ideas are appreciated.