We set up this site for 3-4 months and incoming call to Call mgr DN was working OK. The site reported they did not receive incoming call since 09/17. On the pri router 28xx, the log showed the controller and serial dropped for few ms and turned on automatically. It coincide with incoming call failed. The DN can make outgoing call via the same router and pri line. On ISDN trace, we have Cause i = 0x80A6 - Network out of order
*Feb 18 05:38:53.110: TCP0: bad seg from 172.30.164.13 -- ACK sent to validate RST: port 13075 seq 1502592115 ack 0 rcvnxt 1502592116 rcvwnd 4128 len 0
WE did not change configuration at the call mgr H323 gateway and in 28xx router.
The extension is a valid/registered DN in Call manager. Need some guidance on debug/correct this problem.