Cabletron Systems MMAC-Plus SFCS-1000, Configuration Manual

Page: 402 / 404

g-20
GLOSSARY
Unassigned Cells - a cell identified by a standardized virtual path identifier
(VPI) and virtual channel identifier (VCI) value, which has been generated
and does not carry information from an application using the ATM Layer service.
UNI (User-to-Network Interface) - the physical and electrical demarcation
point between the user and the public network service provider.
UNI 3.0 - the User-to-Network Interface standard set forth by the ATM Forum
that defines how private customer premise equipment interacts with private
ATM switches.
UTP (Unshielded Twisted Pair) - a cable that consists of two or more insu-
lated conductors in which each pair of conductors are twisted around each
other. There is no external protection and noise resistance comes solely from
the twists.
VBR (Variable Bit Rate) - a type of traffic that, when sent over a network, is
tolerant of delays and changes in the amount of bandwidth it is allocated
(e.g., data applications).
VC (Virtual Channel (or Circuit)) - a communications path between two
nodes identified by label rather than fixed physical path.
VCC (Virtual Channel Connection) - a unidirectional concatenation of VCLs
that extends between the points where the ATM service users access the ATM
Layer. The points at which the ATM cell payload is passed to, or received
from, the users of the ATM Layer (i.e., a higher layer or ATMM-entity) for
processing signify the endpoints of a VCC.
VCI (Virtual Channel Identifier) - the address or label of a VC.
VCL (Virtual Channel Link) - a means of unidirectional transport of ATM
cells between the point where a VCI value is assigned and the point where
that value is translated or removed.
VINES (Virtual Network Software) - Banyan’s network operating system
based on UNIX and its protocols.
Virtual Channel Switch - a network element that connects VCLs. It termi-
nates VPCs and translates VCI values. The Virtual Channel Switch is directed
by Control Plane functions and relays the cells of a VC.
Virtual Path Switch - a network element that connects VPLs, it translates VPI
(not VCI) values and is directed by Control Plane functions. The Virtual Path
Switch relays the cells of a Virtual Path.
VPT (Virtual Path Terminator) - a system that unbundles the VCs of a VP for
independent processing of each VC.
VP (Virtual Path) - a unidirectional logical association or bundle of VCs.