Telephony Card Selection


First of all please note that I am new to asterisk and telephony systems in general, so please bear with me.

We have set up a lync server, which is working fine on our internal network for chat/conferencing etc. Now our next step is to integrate our existing pbx system with lync.

As hardware we have an Avaya Integral 5 D pbx box which goes to our Avaya T3-Standard phones via a netConnect AMP 6 panel. After some digging I understood that lync will not support our existing pbx system and that we will need a gateway in between to bridge the gap. This is where I am thinking of including an Asterisk server.

But we will first of all need a telephony card for the Asterisk server to interface with the pbx system. I am willing to keep my current pbx system and extend it with lyncs. Can anyone guide me through choosing the correct and most cost effective telephony card which will be correct for our system? We will have around 50 lyncs terminals (laptops in general) and 15 Avaya T3-Standard phones.

Thank you for any comment,