Digi WAN 3G User Manual page 28

Network services associated with serial ports in general
 RealPort: A single TCP connection manages (potentially) multiple serial ports.
 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.
rsh: Digi devices support a limited implementation of the Remote shell (rsh) protocol, in
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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.
 DialServ: Connecting a DialServ device to the serial port. DialServ simulates a public
switched telephone network (PSTN) to a modem and forwards the data to the serial port.
The Digi device sends and receives the data over an IP network.
Network services associated with the command-line interface
Telnet: A user can Telnet directly to a Digi device's command-line interface.

rlogin: A user can perform a remote login (rlogin) to a Digi device's command-line

interface.
Network/serial clients
A network/serial client connection is one in which a Digi device initiates a network connection or
opens a serial port for communication. There are several categories of network/serial client
connections:
 Autoconnect behavior client connections
 Command-line interface (CLI)-based clients
 Modem emulation (pseudo-modem) client connections
Autoconnect behavior client connections
In client connections that involve autoconnect behaviors, a Digi device initiates a network
connection based on timing, serial activity, or serial modem signals. Autoconnect-related client
connections include:
Raw TCP connection: The Digi device initiates a raw TCP socket connection to a

remote entity.
Telnet connection: The Digi device initiates a TCP connection using the Telnet protocol
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to a remote entity.
Raw TLS encrypted connection: The Digi device initiates an encrypted raw TCP socket
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connection to a remote entity.
Rlogin connection: The Digi device initiates a TCP connection using the rlogin protocol
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to a remote entity.
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