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Glossary

DTE

data terminal equipment: Any device located at the user end of a user-

network interface serving as a destination, a source, or both. DTE includes
devices such as multiplexers, protocol translators, and computers. The con-
nection to a data network is made through data communication equipment
(DCE) such as a modem, using the clocking signals generated by that device.
See also: DCE.

DTR

Data Terminal Ready: An activated EIA/TIA-232 circuit commu-

nicating to the DCE the state of preparedness of the DTE to transmit or
receive data.

DUAL

Diffusing Update Algorithm: Used in Enhanced IGRP, this conver-

gence algorithm provides loop-free operation throughout an entire route's
computation. DUAL grants routers involved in a topology revision the
ability to synchronize simultaneously, while routers unaffected by this
change are not involved. See also: Enhanced IGRP.

DVMRP

Distance Vector Multicast Routing Protocol: Based primarily on

the Routing Information Protocol (RIP), this Internet gateway protocol
implements a common, condensed-mode IP multicast scheme, using IGMP
to transfer routing datagrams between its neighbors. See also: IGMP.

DXI

Data Exchange Interface: Described in RFC 1482, DXI defines the

effectiveness of a network device such as a router, bridge, or hub to act as an
FEP to an ATM network by using a special DSU that accomplishes packet
encapsulation.

dynamic entries

Used in layer-2 and -3 devices to dynamically create a

table of either hardware addresses or logical addresses dynamically.

dynamic routing

Also known as "adaptive routing," this technique auto-

matically adapts to traffic or physical network revisions.

dynamic VLAN

An administrator will create an entry in a special server

with the hardware addresses of all devices on the internetwork. The server
will then dynamically assign used VLANs.

E-1

Generally used in Europe, a wide-area digital transmission scheme car-

rying data at 2.048Mbps. E-1 transmission lines are available for lease from
common carriers for private use.

E.164

1) Evolved from standard telephone numbering system, the standard

recommended by ITU-T for international telecommunication numbering,

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