Asterisk Dial Plan - force insert of prefix
Does anyone know how to force all calls from an extension to add a prefix to the beginning?
We have a pay phone which is on our asterisk server - using the normal school lines to dial out. The problem is, kids are trying to call home at break etc... and not leaving a message. This leads to parents doing 1471 and calling the school demanding to know who called them and why.
What we want to do is insert 141 in front of all calls dialled from that phone. So, if they call 842134, the asterisk server will actually dial 141842134.
Any ideas how to do this?
Doing a google search for asterisk and prefix turns up about 1,000,000 irrelevant items...