ADTRAN Express L128T S User Manual page 181

hop count
A routing metric used to measure the distance between a
source and a destination. Particularly used by RIP.
hub
(1) Communications center, (2) Major routing station for con-
necting channels, (3) DDS connecting center.
IEEE
Institute of Electrical and Electronic Engineers. Professional
organization that defines network standards. IEEE LAN stan-
dards are the predominant LAN standards today and include
protocols similar or virtually equivalent to Ethernet and To-
ken Ring.
IEEE 802.1d
An algorithm used to prevent bridging loops by creating a
spanning tree.
IEEE 802.2
An IEEE LAN protocol that specifies an implementation of
the LLC sublayer of the data link layer. It handles errors,
framing, flow control, network layer (Layer 3) service inter-
face, and is used in LANs.
IEEE 802.3
A physical layer standard specifying a linear bus network
LAN with a CSMA/CD access method on a bus topology.
Ethernet follows the 802.3 standard, transmitting at 10 mega-
bits per second. This is the most common local area network
specification. Physical variations of IEEE 802.3 include
10Base2 and 10BaseT.
in-band signalling
Signalling made up of tones which pass within the voice fre-
quency band and are carried along the same circuit as the talk
path being established by the signals. Virtually all signalling
(request for service, dialing, disconnect, etc.) in the U.S. is in-
band signalling. Most of that signalling is MF (Multi-Fre-
quency) dialing. The more modern form of signalling is out-
of-band.
interexchange carrier
Since divestiture, any carrier registered with the FCC autho-
rized to carry customer transmissions between LATAs inter-
state, or if approved by a state public utility commission,
intrastate. Includes carriers such as AT&T Communications,
Satellite Business Systems, GTE Telenet, GTE Sprint, and
MCI.
information element
The name for the data fields within an ISDN Layer 3 message.
61202070L3-20 Express L128T S/T User Manual
Glossary
Glossary-3