Configuring and Managing Telnet Servers 13-19
Configuring a Raw TCP Listener
Configuring a Raw TCP Listener
Introduction
When you configure a Telnet listener to use raw TCP, the associated port sends data to
a device or a remote host without any data manipulation or interpretation of control
characters. Because raw TCP sends the data it receives to a port without any
interpretation, sending data this way is faster than using the Telnet protocol. The raw
TCP listener also allows an application program on a remote host to use single socket
I/O (input/output) calls and bypass the Telnet protocol layer.
When To Use Raw TCP
Using raw TCP is beneficial when you need to maintain the control character
definitions in the data you send to and from a port on the access server or when you
need to send data without any Telnet processing. For example, when sending data to a
printer, you may need to preserve the control characters sent to the printer or you may
need to run socket I/O calls. In these cases, you want to configure the raw TCP protocol
on the Telnet listener.
Configuring Raw TCP
To configure raw TCP on an access server, configure a Telnet listener that has a type
of RAW. Use the CHANGE TELNET LISTENER TYPE RAW command to
configure the Telnet listener. Then use the CHANGE TCP LISTENER or CHANGE
TELNET LISTENER commands to define additional characteristics.
Example: Configuring Raw TCP
The following example shows how to a configure raw TCP listener on port 3:
L
ocal>
CHANGE TELNET LISTENER 2003 PORT 3
L
ocal>
CHANGE TELNET LISTENER 2003 TYPE RAW
Local>
CHANGE TELNET LISTENER 2003 CONNECTIONS ENABLED
These commands:
• Create a Telnet listener on access server port 3 and assign TCP port 2003 to the
port.
• Set the type for the Telnet listener to RAW.
• Enable the raw TCP listener.
