Page 592

Glossary

553

dynamic entries

Used in layer 2 and 3 devices to 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 assign dynamically used VLANs.

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

rying data at 2.048Mbps. E1 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,
particularly in ISDN, SMDS, and BISDN. 2) Label of field in an ATM
address containing numbers in E.164 format.

E channel

Echo channel: A 64Kbps ISDN control channel used for circuit

switching. Specific description of this channel can be found in the 1984 ITU-
T ISDN specification, but was dropped from the 1988 version. See also: B,
D, and H channels.

edge device

A device that enables packets to be forwarded between legacy

interfaces (such as Ethernet and Token Ring) and ATM interfaces based on
information in the data link and network layers. An edge device does not
take part in the running of any network layer routing protocol; it merely uses
the route description protocol in order to get the forwarding information
required.

EEPROM

Electronically Erasable Programmable Read-Only Memory:

Programmed after their manufacture, these nonvolatile memory chips can be
erased if necessary using electric power and reprogrammed. See also:
EPROM, PROM.

EFCI

Explicit Forward Congestion Indication: A congestion feedback

mode permitted by ABR service in an ATM network. The EFCI may be set
by any network element that is in a state of immediate or certain congestion.
The destination end-system is able to carry out a protocol that adjusts and
lowers the cell rate of the connection based on value of the EFCI. See also: ABR.

www.sybex.com