A TCP/IP session that is inactive for more than one minute may be disconnected when you connect to a terminal server from a Windows Server 2003 SP1-based computer

Consider the following scenario:

• You are using a Microsoft Windows Server 2003 Service Pack 1 (SP1)-based computer.
• You connect to a server that has Windows Server 2003 Terminal Server enabled or to any application that uses TCP/IP.
• The connection passes through a Microsoft Internet Security and Acceleration (ISA) Server 2000-based computer in the outgoing direction.
• The connection stays inactive for more than one minute.

In this scenario, the TCP/IP session may be disconnected by the ISA 2000 Server-based computer.

Note If you use a Terminal Server client computer to connect to the terminal server or to an application that uses TCP/IP, the client computer automatically reconnects most of the time. When this occurs, you may not notice any interruption in the connection. However, if a custom application uses custom authentication to create a specific connection, and if this custom application starts connection by using an ActiveX control, the connection will lose the authentication integrity after it is disconnected by the ISA Server 2000-based computer. In this case, the client computer may not be able to automatically reconnect.

This problem occurs because the network address translation (NAT) mappings on the ISA Server 2000-based computer incorrectly time out after one minute of inactivity.

To resolve this problem, upgrade the ISA Server 2000-based computer to ISA Server 2004.

To work around this problem, make sure that there is some traffic between the client and the server in either direction at intervals less than one minute. For example, configure the TCP/IP session to display the system clock because the system clock typically causes repeated traffic at short intervals of less than one minute.