How to dial through to extension on another PBX

Im having some trouble figuring out how to set this up. Basically I have two asterisk boxes (both with freepbx). Both machines have IAX trunks between them - with outbound routes for the other boxes extension mask. From each office you can call the other office fine. However, I need the ability for people calling into office 1’s IVR to be able to enter an extension on Office 2 - and have it ring there.

Right now - you get the “im sorry thats not a valid extension”

Is this a context thing? If so - how do i set it up.

Also - in case its important, these boxes are IAX trunked with 15 other PBXs - but we do not need the “dial through” capability there.

Thanks in advance for the help!


I, too, have a need to pass calls from one Asterisk box to both a Toshiba CIX-670 and a second Asterisk box.

What I did was to set up all the extensions in the company on the primary Asterisk box. If the extension is physically on the Toshiba, I use a custom extension pointing to a ZAP trunk group. If the extension is on the secondary Asterisk box, I configured the custom extension to use the IAX trunk between the two boxes. (The “PBX in a Flash Without Tears” book helped here. See page 128 for an example.)

If you haven’t found you are in for a treat. There is a lot of good stuff there, including a link to the above mentioned book.

There is probably a cleaner and better way to configure this type of system, but the way I did it works. As long as the trunks are configured properly so the two boxes talk, you should be OK.