3Com HomeConnect 3CP4130 User Manual page 42

Modem Dual Link, it is typically used only in the case of disaster recovery.
DHCP (Dynamic Host Configuration Protocol)
This allows a device to have a different IP address every time it connects to the
network or, in some cases, to change while it is still connected. The software
keeps track of IP addresses. This allows a new computer to be added to a network
without having to manually assign it a unique IP address.
DIP switch
A series of tiny switches built into circuit boards. DIP switches let you configure
a circuit board to conform to a particular application. In the case of your Dual
Link modem, the DIP switch is reserved and all toggle switches should be left in
the Off position.
DSL (Digital Subscriber Line)
The two main categories of DSL currently are the ADSL (Asynchronous DSL)
and SDSL (Synchronous DSL). DSL technologies pack data onto copper wires.
They are used for connections from a telephone switching station to a home or
office, not between switching stations. DSL is similar to ISDN in that both
operate over existing copper telephone lines (POTS) and both require the short
runs to a central telephone office (usually less than 20,000 feet). But DSL offers
much higher speeds.
Encapsulation
In networking, encapsulation means wrapping a data set in a protocol header. This
allows one network to send its data via another network's connections.
Ethernet
Ethernet is a LAN (local area network) protocol that was developed by Xerox
Corporation in cooperation with DEC and Intel in 1976. It is one of the most
widely implemented LAN standards. Its function is to move data packets from
one computer to another.
Flash Memory
An area on the modem where basic information necessary to operate the modem
is stored. In your modem Dual Link, it contains a program with the extension
".nac" which must be easy to update but not easy to erase. A utility provided on
your installation CD, if you install it on your PC, can search for any updates to the
Nac file from the 3Com web site.
Host
The word Host has several different meanings in the computer industry. The
"host" can be referred to as the computer system that is accessed remotely by
modem over telephone lines by a user sitting at a remote terminal. It has also
come to mean any computer connected to a TCP/IP network, including the
Internet. Each Host has a unique IP address. "To host", on the other hand, means
to provide the infrastructure for a computer service, as, for example, to "host"
Web servers, where the hardware, software and communication lines are provided
and controlled by the company providing the server while the content on the
server is controlled by the user.