I need to make a rule to prevent a prefix of being dialed

[wdcsinc]

Hi all I need to make a rule that will prevent a prefix to be dialed from specific extension only for example I do not want any number starting with 1809 to be dialed from extension 102, how do I acomplish that task? please help it is very important, these calls are going out via my voip provider Broadvoice, please advice.

 

[5qg4]

Calls to Numbers starting with : 1809
Calls from extension(s) : 101;103-105
Transform mask : rrrr

Assume you have extensions 101 to 105. The above setting for prefix 1809 only allow 101,103,104,105. If EXT 102 dial 1809+PSTN number will got the busy tone.