Hello Michael, and thank you for using the ADTRAN Support Community.
The event "BRI LT: SPID xxxxxx21620101 - NOT IN L" means the SPID listed was sent to the ATLAS. The full message ends with "NOT IN LIST" meaning the SPID was received, but is not configured on the port it was received on. If you are receiving events for Slot 1 Port 4, then it MUST be in the DIAL PLAN somewhere - either as a USER TERM or a NETWORK TERM, and it is receiving the specified SPID(s). If the port is not configured in the DIAL PLAN it will not display any events in the SYSLOG. So whatever is connected to the port is trying to register the SPIDs the ATLAS is receiving.
The fact that Slot 2 Port 2 is assigned "2166" would explain why it is giving the above error when it receives the SPID of "xxxxxx21620101". It sounds like you have equipment connected to the wrong ports in the ATLAS, or just mis-configured. Having the wrong SPIDs will not prevent outbound calls, but it will prevent inbound calls from being routed to the BRI port (because the SPIDs must be registered in order to route the call out the BRI interface).
Hope this helps,
Thanks, Patrick. That seems to be the problem. Apparently, somehow, a couple of the cables got plugged into the wrong ports. Correcting that clears up the problem.