Remote conference

I have two FreePBX systems setup and I have them trunked together via IAX. I want to setup a conference room on one and have the other be able to dial in direct.
What I have done i set up the conference room and a route on the remote box that dials its extension number. However the calls don’t go to the conference room they simply hang up. I have also tried setting up a IVR and then directing to the conference but still no go.
Any help or ideas much appreciated.