Core Issue
This problem manifests itself as an inability for the users to enter their passwords or to respond to voicemail prompts.
Resolution
The gateway must be configured to pass Dual-Tone Multifrequency (DTMF) tones.
When accessing voicemail, commands for password access and menu navigation must be entered with the telphone keypad. On some gateways the DTMF tones are not passed. To pass DTMF tones out of band the command dtmf-relay h245-alphanumeric must be configured under the VoIP dial-peer which has the voicemail service.
For example:
dial-peer voice 1000 voip
destination-pattern 5555...
session target ipv4: 10.1.1.1
codec g729ar8
dtmf-relay h245-alphanumeric
For more information, see Cisco Unity Does Not Respond to Touchtones.
