- Wire Inc. Intelligent Gateway User Guide

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D
Data Link. The communications link used for data transmission from a source to a destination. For
example, your telephone is a data link.
Data Transfer Rate. The average number of bits per unit of time passing in a data transaction.
Dedicated Connection. A communication link that operates constantly.
DHCP. See Dynamic Host Configuration Protocol.
Dial-up Connection. A data communication link that is established when the communication equipment
(e.g. a modem) dials a phone number and negotiates a connection with the equipment on the other end of
the link.
Digital Signal. A signal that takes on only two values, off or on, typically represented by “0” or “1.”
Digital signals require less power but (typically) require more bandwidth than analog.
Digital Subscriber Line Access Multiplexer (DSLAM). A device found in telephone company telephone
exchanges that takes a number of DSL subscriber lines and concentrates them onto a single ATM line.
Discrete Multi-Tone Modulation (DMT). A method of transmitting data on copper phone wires that
divides the available frequency range into 256 sub-channels or tones, and which is used for some types of
DSL.
DMT. See Discrete Multi-Tone Modulation.
DNS. See Domain Name System.
Domain Name System (DNS). The protocol used for assigning text addresses (such as www.bt.com) for
specific computers and computer accounts on the Internet.
DSLAM. See Digital Subscriber Line Access Multiplexer.
Dynamic Host Configuration Protocol (DHCP). A TCP/IP protocol that allows servers to assign IP
addresses dynamically to PCs and workstations. The PC or workstation “borrows” the IP address for a
period of time, then the IP address returns to the DHCP server for reassignment.
E
E-1. A dedicated digital communication link provided by a European telephone company that offers 2.048
Megabits per second of bandwidth, commonly used for carrying traffic to and from private business
networks and Internet service providers.
Echo Cancellation. The elimination of reflected signals (“echoes”) in a two-way transmission created by
some types of telephone equipment, used in data transmission to improve the bandwidth of the line.
Encapsulation. The technique used to layer protocols.
Ethernet. A type of local area network that operates over twisted wire and cable at speeds of up to 10
Mbps.