Axapta 3.0 CRM and TAPI

Hello: We are proceeding pretty well with our Axapta 3.0 implementation, but are hitting some snags with our understanding of how TAPI integration needs to happen. Our PBX vendor (Avaya) presents that we simply need to upgrade our CT Server software in order to bring the Definity G3R we have up to TAPI compliance. Our Axapta reseller is presenting that we need a cable to connect each Axapta client computer to the phone that resides on their desk. For the time being we are wanting to capture ANI/Caller ID and populate screens based on that. Eventually we want to add predictive out-dialing features, etc. Has anyone gone down this road yet? Even if you do not have the same phone system, I would really like to discuss your experiences. Thanks Daniel Pumphrey