General Commands

2.3TCP Echo commands

The following are the TCP Echo commands:

•tesend on page 2-17

•tesinit on page 2-18

•teshalt on page 2-18

•techalt on page 2-19

•testats on page 2-20.

These commands are included in the menu list if TCP_ECHOTEST was defined in ipport.h.

General Commands

2.3.1tesend

The tesend command opens a TCP Echo Client for the server (if one is not already open) and sends a TCP packet to the TCP Echo Server.

This command is included in the menu list if TCP_ECHOTEST was defined in ipport.h.

Syntax tesend

Example

INET> host 10.0.0.20 INET> tesend

All TCP Echo Client connections are in use. Please try at a later time.

INET> tesend

sending TCP echo 0 to 10.0.0.20

INET> TCP echo reply from:10.0.0.20, len:64, reply:0,Our send#:0 INET> Deleting idle TCP Echo Client.

INET> _

Usage

The IP address of the TCP Echo Server is specified using the host command (see host on page 4-24).

The maximum number of open TCP connections on which select() can be used is defined in FD_SETSIZE in tcpport.h. TCP Echo Client uses select() which has a default value of 2. Therefore, by default, only one TCP Echo Client can be open because the other connection is used for TCP Echo Server.

By default, an idle TCP Echo Client is deleted after 10 minutes. This is defined in

TCP_IDLE_TIMEOUT.

See also

An associated command is delay on page 4-23.

General Commands

2.3.2tesinit

The tesinit command starts the TCP Echo Server on the console, if it not already running.

This command is included in the menu list if TCP_ECHOTEST was defined in ipport.h.

Syntax tesinit

Example

INET> tesinit

tcp echo srv - starting. INET> _

Usage

Because TCP Echo Server and UDP Echo Server usually start up with the application and close when the application quits, the tesinit command is not often used.

2.3.3teshalt

The teshalt command closes the TCP Echo Server (on the console) if it is running. This command is included in the menu list if TCP_ECHOTEST was defined in ipport.h.

Syntax

teshalt

Example

INET> host 10.0.0.22 INET> teshalt

tcp echo srv - closing. INET> _

General Commands

2.3.4techalt

The techalt command closes the TCP Echo Client connection.

This command is included in the menu list if TCP_ECHOTEST was defined in ipport.h.

Syntax

techalt

Example

INET> techalt

Closing TCP Echo Client.

INET> _

Usage

A TCP Echo Client sends packets to an TCP Echo Server, then the server sends them back. This mechanism is used to test the functionality of TCP protocol.

Note

Multiple Client connections can be open on the console, with one Client connection through the console interface. If a Telnet server is implemented in the console, another computer can make a Telnet connection to the console, and open a Client connection.

So, although only one TCP Echo Server can be running on the console, there can be multiple TCP Echo Clients.