Network connections and data paths Network/serial clients
Digi ConnectPort LTS User Guide
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n Modem: The Modem Profile allows you to attach modem devices to the serial port to establish
or receive connections from other systems and modems. Both the modem dial-in and bi-
directional options provide a login from the Digi device.
n Reverse SSH: A remote entity establishes an SSH connection to a ConnectPort LTS serial port
and data passes transparently between the SSH connection and a named serial port.
Network services associated with serial ports in general
The following list details network services associated with serial ports in general.
n RealPort: A single TCP connection manages (potentially) multiple serial ports.
n Modem emulation, also known as pseudo-modem (pool): A TCP connection to the “pool” port
is interpreted as an incoming call to an available pseudo-modem in the “pool” of available port
numbers.
n rsh: ConnectPort LTS products support a limited implementation of the remote shell (rsh)
protocol, in that a single service listens to connections and allows a command to be executed.
Only one class of commands is allowed: a single integer that specifies which serial port to
connect to. Otherwise, the resulting connection is somewhat similar to a reverse telnet or
reverse socket connection.
Network services associated with the command-line interface
The following list details network services associated with the command line interface (CLI).
n SSH: Use Secure Shell (SSH) to directly access a ConnectPort LTS command-line interface.
n Telnet: Use telnet to directly access a ConnectPort LTS command-line interface.
n Rlogin: Perform a remote login (rlogin) to a ConnectPort LTS command-line interface.
Network/serial clients
A network/serial client connection occurs when a ConnectPort LTS product initiates a network
connection or opens a serial port for communication. There are several categories of network/serial
client connections:
n Autoconnect behavior client connections
n Command-line interface (CLI)-based client connections
n Modem emulation (pseudo-modem) client connections
Autoconnect behavior client connections
In client connections that involve autoconnect behaviors, a ConnectPort LTS product initiates a
network connection based on timing, serial activity, or serial modem signals. Autoconnect-related
client connections include:
n Raw TCP connection: The ConnectPort LTS initiates a raw TCP socket connection to a remote
entity.