Swapping out an AS5200 running 11.3 with an AS5300 running 12.3. Copied the same config from the 5200 to the 5300. ISDN Pri calls from remote routers to the 5200 connect and stay connected. Calls from the same router to the 5300 disconnect after 1 sec. Q931 debug shows x8090 disconnect code being sent from the 5300. Suspect AAA auth issue because I don't see any attempts logged in tacacs server (CiscoSecure). When I debug ppp auth the only thing out of the ordinary is a "PPP Authorization Required" message but the AAA author configs are the same on both 5200 and 5300. When I run a debug on tacacs on the 5300 I see "pass" statuses coming back from the server.