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:

Local> CHANGE TELNET LISTENER 2003 PORT 3

Local> 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.

Configuring and Managing Telnet Servers 13-19