Specifications

©
2002, David K. Z. Harris
16
Pg. 16
© 2002
David K. Z. Harris
Terminal Server Disadvantages
Ø It’s not cheap to deploy.
Ø Only one person can connect to
a given port at one time.
Ø Hard to tell who is connected, if
a given port is already busy.
Ø Difficult to kick someone off if
you need to access a port.
Ø If nobody is connected to a port,
incoming data is lost, not logged
Reverse TCP connections are good, and useful. But when you are done with a
connection, you must release the connection, or others will not be able to
connect to it.
If a port is already in use, your connection is refused, but you don’t know who
is connected. You will need login privileges on the terminal server to try to
find out, and to reset the port to clear that session. Such access to the terminal
server would normally be restricted to a few users, which may make it difficult
to clear a port quickly.
If nobody is connected, data coming in from attached devices is usually lost
forever. (Lightwave Communications 3200 series servers have a 64KB-per-
port cyclic buffer, so you do retain some port data if nobody is connected.)
With a logging Console Server application, the application makes the original
reverse-TCP connections to all the ports you care about…any incoming data is
logged, and (multiple) clients can connect to the (same) sessions through the
application server.