Digi WAN 3G User Manual page 209

modem emulation
A serial port configuration where the port acts as a modem. The Digi device emulates modem
responses to a serial device and seamlessly sends and receives data over an Ethernet network
instead of a Public Switched Telephone Network (PSTN). The advantage for a user is the ability
to retain legacy software applications without modification and use a less expensive Ethernet
network in place of public telephone lines. Also known as pseudo-modem or pmodem.
NAT
NAT (Network Address Translation) is the translation of an Internet Protocol address () used in
one network to a different IP address known in another network through a NAT table that does
the global-to-local and local-to-global IP address mapping. This increases security since each
outgoing or incoming request must go through a translation process that also authenticates the
request or matches it to a previous request. NAT can be statically defined or it can be set up to
dynamically translate from and to a pool of IP addresses. NAT also conserves on the number of
global IP addresses needed and it uses a single IP address in its communication with the world.
port forwarding
A serial port configuration that sends data directly to a specific port instead of the path
determined by the router based on traffic.
Power-On Self Test (POST)
When power is turned on, POST (Power-On Self-Test) is the diagnostic testing sequence that a
computer's basic input/output system (or "starting program") runs to determine if the computer
keyboard, random access memory, disk drives, and other hardware are working correctly.
If the necessary hardware is detected and found to be operating properly, the computer begins to
boot. If the hardware is not detected or is found not to be operating properly, the BIOS issues an
error message which may be text on the display screen and/or a series of coded beeps, depending
on the nature of the problem.
provisioning
The process of configuring a mobile (cellular) device with the required configuration used to
access the mobile network.
RealPort
Patented Digi software for COM port redirection. RealPort makes it possible to establish a
connection between the host and networked serial devices by creating a local COM or TTY port
The COM/TTY port appears and behaves as a local port to the PC or
on the host.
server.
This process of COM port redirection allows existing software applications like DNP3
and Modbus to work without modification. Unlike other COM port redirectors, RealPort offers
full hardware and software flow control, as well as tunable latency and throughput. These
features ensure optimum performance, since data transfer is adjusted according to specific
application requirements.
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