Setting up Quintum Tenor AF with FreePBX

I have been trying to setup a Quintum Tenor AF as a gateway to connect my Vonage ATA to Asterisk (FreePBX) and have tried searching forum posts here and elsewhere regarding this for quite some time without luck.

I am using FreePBX and Quintum Tenor AF series with 4 FXS/FXO ports. I have a Vonage account and a Vonage ATA.

The setup is as below:

Cisco 7940 <-> Asterisk <-> Quintum <-> Vonage ATA <-> Vonage Phone

I have so far managed to register Quintum as an extension on FreePBX and have configured the SIP setting on the Quintum correctly (or atleast I think so). However when I try to call Quintum’s extension through the Cisco IP Phone all I hear is a fast busy.

If anyone has prior experience in getting a similar setup to work, I would really appreciate any help. Also if there is some other information you would like me to post here to shed more light please do let me know.

Sorry if I have violated any posting rules.