How to extend caller id?


This is probably a common question.

Our Asterisk PBX is internally connected to Cisco SIP phones and externally connected to plain old telephone system. For outgoing calls, we need to prefix “9” for the phone number.

When a call comes in, on the Cisco phone we can see the number it is coming from. However, we cannot just dial the same number out without editing it and prefixing it with 9.

Is there a way to extend the caller id to automatically add 9 before it is sent to the Cisco phone?

Thank you in advance for your help.


Don’t do that. Because if you do, you won’t be able to mach caller id number with some data in database. It would be better to put 9 in dial plan of your Cisco phones. So whenever sombody dials 7 digit number, to get 9 in front of it.