Forward DID from ISDN PRI through IAX trunk to another FreePBX


I have two FreePBX servers, the first is a machine with ISDN PRI, with 100 DID’s assigned, which I manipulate with Incomning routes. I’m having problems mentioned in the subject. I’m trying to allocate part of my DID’s to another PBX, so I could create Inbound routes based on DID on the second PBX.

First I created IAX trunk which is working just fine. When I try to set Inbound route for some DID to go to second PBX (destination IAX trunk), the call gets forwarded to second PBX, not with DID, but as a call to an extension number which is the same as the DID…

FreePBX is on the first server, FreePBX on the second.

Sorry if my question is a bit confusing, I’ll give more details if needed.