Use this entry to set the phone number that will be used for signaling with call forwarding.
Note: This phone number will only be used if the parameter  is set to "Custom-ID".
    - SNMP ID:
 - 2.33.3.4.13
 - Console path:
 - Setup > Voice-Call-Manager > Users > Extensions
 - Possible values:
 Max. 64 characters from [A-Z][a-z][0-9]#@{|}~!$%&'()*+-,/:;<=>?[\]^_. `
- Default:
 - empty