@Derelict We actually have 2 phone systems from a merger. A on premise phone system (that works great) and AT&T hosted voice. Calls on the AT&T drop randomly. AT&T refuses to be of any help because it's a network problem and to be fair if i put the phones on a router with the udp timeout changed it does work.
The reason I am trying to move it off the current router is QOS. Which has been a problem before because we were running 3 routers for different network segments off the same internet connections and 1 router could use all the bandwidth and starve the other routers.