Connections Timing Out

Introduction

There are many things that control a connection for Anzio Lite and AnzioWin. This includes network devices, the host application, the host operatiing system, user login scripts, Microsoft Windows settings and more.

Neither Anzio Lite nor AnzioWin contains any idle time out features. Likewise, Windows does not contain any idle time out features that could cause problems.
 
Telnet and Secure Shell (SSH) connections are stateful connections and must be up and available whenever a character of any type is passed either direction. If not, the user's connection can be dropped and thus, depending on the settings in Anzio, the Anzio window may close. This type of failure usually indicates some network or server action timed out, or the network connection was not available.
 
This is different than how the FTP (file transfer) or HTTP (web browser) protocol behaves, these protocols simply try to reconnect since no login is necessary.

How Anzio Behaves 

If a network connection (telnet or Secure Shell, SSH) receives a drop or a network error, the Windows network drivers will cause an error to be sent to AnzioWin or Anzio Lite. As soon as Anzio triesd to utilize the network, it will notice the error and sever the connection to the host.

The behavior of Anzio is controlled via an option under the Communicate menu and the On-line Drop option. You can set this either for "Reconnect", in which case you will be asked to re-log in, for "Stay Running, Unconnected" where you can see any errors, but are not connected, or "Quit", which is the usual default used- to quit when a connection disappears.

What May Cause This

A number of network issues may cause the problem of a dropped or timed-out connection.

• Many connections over the Internet through an ISP (Internet Service Provider) can have problems if not set for "Stateful" connections (web and FTP are "stateless" and do not track logged-in user information and hence may work fine whereas telnet and Secure Shell fail).
• Drops can also occur when a local hub, router or network switch is not properly configured or when one of these devices is beginning to fail (generating errors).
• If a network card or connection gets too many network errors, many network devices will also drop the connection, i.e. if there is a wiring or a failing network port on a hub or switch.
• If Windows or the host operating system receives too many network errors, then the connection can be dropped.

Scripting for inactivity can be a problem. Host scripts, software or even the host application can also cause a time out or dropped connection if there is a specified period of inactivity.

• Often administrators will set host-end login scripts or .profile scripts to time out if there is a certain period of inactivity. Look through the various shell and login scripts for a "tout" or "tmout" setting.
• Some applications depend on these scripts or run their own that can also watch for inactivity.
• Many network devices can watch for inactivity and clear a table, reset a connection, or in general drop the current connection when idle.

Possible Solutions

There are some options a user can do to try to get around the issue of dropped connections:

a) Contact your ISP and let them know you are doing telnet or secure shell connections and the connections are dropping (if you get the right tech person, he/she will know what is mis-set in your connection to them).
 
b) Check your devices in-house and see if one of them is getting errors in their log file. If they are unmanaged devices, switch ports and see if the problem moves.
 
c) Make sure the host system is not timing out. There should not be a "tmout" or "tout" inside your host script files (.profile or login scripts). Also make sure the host and PC network cards are not generating any network errors.
 
d) Try setting the "Stay Alive" parameter (available in version 15 or later).

Check under the Communications menu and Network : Stay Alive. This option, when set greater than zero, will send a single empty packet over the network stating that Anzio is still alive and working (typically set this for 30 seconds). However, setting this option too low may only show the problem earlier and more often and not really hide it. Again this option is masking some other problem or mis-configuration, but it will help in about 80% of the cases.

Conclusion

AnzioWin and Anzio Lite do not have any built in time out features. If you are getting dropped connections, it is most likely due to some network problem or host setting. AnzioWin and Anzio Lite hqave a feature to "mask" this, the Stay Alive menu item. However, you should try to track down the real problem - which may not be easy to do.

Check out the following pages for more information:

• A Guide to Telnet
• Troubleshooting a Telnet Connection