VOIP Qos on DLink Dir-655

[Sandan]

I have been searching and can't find information on my question. I just got the Dlink Dir-655 router and want to make sure the Qos gives priority to my CallVantage VOIP. My Telephone Adapter is the Dlink dvg-5102s. Anyway to make sure the Qos functions should I put the TA behind the router? Currently have it between the modem and router. It would make sense to have it after the router but I'm no expert on these matters. Thanks.