Lantronix ETS Reference Manual - page 33
Concepts
LAT and TCP/IP Connectivity
2-15
Ping
Sends a TCP/IP request for an echo packet to another network host to test
network connections.
Send
Enables users on Telnet session to send explicit Telnet control characters, such
as Abort Output (AO), Are You There (AYT), and more.
2.8 LAT and TCP/IP Connectivity
The service capabilities of the ETS also allow translation between LAT and Telnet protocols. For example,
a user on a LAT host might see and connect to an ETS offering service ernie as a LAT connection. This
“service” might actually be a Telnet connection to host ernie. In the other direction, a TCP/IP user can use
the UNIX Telnet or Rlogin command to connect to a LAT host through the ETS.
Both cases can take place transparently to the user. This implies that the TCP/IP host does not need LAT
software, nor does the LAT host need additional TCP/IP software. The only difference between the
connection types is their setup. One should keep in mind that each such connection consumes ETS memory
and processing resources because each is treated as a connected “port” and user on the ETS. Chapter 7, TCP/
IP Host Setup, explains how to set up Telnet to LAT and LAT to Telnet translations.
2.8.1 Connection Methods
The mechanics of the protocol translator add the ability to actually connect to the ETS from either a TCP/
IP host (using Telnet or Rlogin) or a LAT host. For example, if the ETS’s IP address is 192.0.1.92, a Telnet
connection from an IP host to this address will return the local prompt just as if the user had logged in on a
hardwired port. Also, the ETS can advertise itself as a “service” to LAT hosts. That is to say, LAT hosts can
connect to the server and obtain the local prompt.
Once an incoming (LAT or Telnet) connection has been started, users can use the server as if they were
connected on a local port. They can start outgoing connections, connect to local services, configure the
server, and so on. TCP/IP users then have a convenient way to remotely “manage” the server: managers can
simply log in and become the privileged user, change server parameters, and log out again.
2.8.2 Environment Strings
The ETS can be configured to set up sessions according to the host to which it is connected. These
environment settings can be supplied via the Connect command, or can be saved either as part of the
preferred or dedicated hostname or as part of a virtual translation service. Most of the environment options
mimic the Set Session command options.
The environment string is a sequence of key letters, sometimes prefixed by a plus (+) or minus (-). The keys
are added after the hostname and a colon for Telnet or Rlogin connections, and are specified via the
EnvString parameter for LAT connections. The available key letters are explained in the Connect command
on page 12-9.
Key letters are not case-sensitive, and no white space is allowed in the environment string. In addition,
commands that oppose previously-configured settings will overwrite the previous setting, even if they
appear on the same command line.