User manual

Supported connections and data paths in Digi devices

Digi devices allow for several kinds of connections and paths for data flow between the

Digi device and other entities. These connections can be grouped into two main

categories:

 Network services, in which a remote entity initiates a connection to a Digi

device.

 Network/serial clients, in which a Digi device initiates a network connection or

opens a serial port for communication.

This discussion of connections and data paths may be helpful in understanding the effects

of enabling certain features and choosing certain settings when configuring Digi products.

Network services

A network service connection is one in which a remote entity initiates a connection to a

Digi device. There are several categories of network services:

 Network services associated with specific serial ports

 Network services associated with serial ports in general

 Network services associated with the command-line interface (CLI)

Network services associated with specific serial ports

Network service connections associated with specific serial ports include:

 Reverse Telnet: A telnet connection is made to a Digi device, in which data is

passed transparently between the telnet connection and a named serial port.

 Reverse raw socket: A raw TCP socket connection is made to a Digi device, in

which data is passed transparently between the socket and a named serial port.

 Reverse TLS socket: An encrypted raw TCP socket is made to a Digi device, in

which data is passed transparently to and from a named serial port.

 LPD: A TCP connection is made to a named serial port, in which the Digi

device interprets the LPD protocol and sends a print job out of the serial port.

 Modem emulation, also known as Pseudo-modem (pmodem): A TCP

connection is made to a named serial port, and the connection will be

“interpreted” as an incoming call to the pseudo-modem.