Users getting kicked out of sessions

We have an old (11.11) HP-UX system. A couple of months ago, our customers started having problems with their logins.

After sitting idle for roughly an hour, their screens would lock up and they would be kicked out of the system. This happens if they are in the application or on the command line. I have verified that this is happening by leaving a putty session (at the command line) open.

I have checked for any kind of "timeout" on the system and cannot find anything.

We use SSH (telnet is disabled). I have looked thru the syslogs and the customers' profiles. Please let me know if there is any where else I should be looking.

ssh has by default some timeout configured... I cant remember where though... So was ssh introduced in replacement of telnet at the time first issues appeared?
I can t remember well of the issue but it seemed to happen on solaris connection when connecting to HP boxes...
I never had any issues of the sort from my PC (with RX...) or between HP boxes unless there was a TIMEOUT set somewhere ( like /etc/profile...).
I have more vicious issues that looks similar to you but are random, since I cant explain ( Im no network engineer) though I know the cause I cant get anthing done about it: Network team have started to use probe devices... and when they get on a server they act almost like a hacker... scanning all ports etc... finally if a server has NFS on it, it goes bezeurk...
So NFS can also cause such issues ( tranfer of huge files... )

Look if you cant monitor your network devices on your box...

I found out that the telecom group added a firewall to this system around the time the issues started. I am verifying if that is the issue.

I did check SSH but, the timeout had been disabled. And, it has been running on this server since it was first built several years ago.

I will update asap.