I've got a slightly strange issue that I am struggling to trace ...

using sqlplus or pls/developer connecting to one of our remote customers keeps coming up with this error when selecting from any fairly large table or trying to recompile any function / procedure

ORA-03113: end-of-file on communication channel

If I connect to any other remote customer (dozens of different servers all in different facilities) and access a large table or compile any routine there are no issues at all.

There are two servers in the same facility and I have the same issue connecting to databases on either server which suggests its not a database or listener issue (cant see any errors in the listener.log). I've rebooted both servers and I can use sqlplus or pl/sql developer on the servers and can access the data with no problems.

I can connect to the servers via NetSupport and transfer files fine and the Apache server in the same facility can be accessed with no issues so it only seems to be oracle network traffic that is the issue.

Has anyone experienced anything similar ... any ideas how to even trace where it's breaking down?