IBM xSeries 300, Service Manual

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UNI. User network interface.
UPC. Usage parameter control.
URL. Uniform resource locator.
user network interface (UNI). A standardized
interface between a user and a communication network.
UTC. Universal time, coordinated.
UUS. User-user signaling.
VBR. Variable bit rate.
VC. Virtual channel.
VCC. Virtual channel connection.
VCI. Virtual channel identifier.
VCN. Virtual circuit number.
virtual channel (VC). In ATM, a unidirectional route
between two ATM devices. Virtual channels always
come in pairs, one in each direction. They follow virtual
paths.
virtual channel connection (VCC). In ATM, a
unidirectional connection established over a virtual
channel. Virtual channel connections always come in
pairs, one VCC in each direction.
virtual channel identifier (VCI). In ATM, the unique
numeric tag that identifies every channel. It is defined
by a 16-bit field in the ATM cell header.
virtual connection. In frame relay, the return path of
an FR potential connection.
virtual path (VP). In ATM, a group of virtual channels
that are switched together as one unit. (Also called VC
service.)
virtual path connection (VPC). In ATM, a connection
established over a virtual path. Virtual path connections
always come in pairs, one VPC in each direction. (Also
called VP service.)
virtual path identifier (VPI). In ATM, an 8-bit field in
the ATM cell header that indicates the virtual path over
which the cell is to be routed.
voice server adapter (VSA). In an Nways Switch, a
module that supplies additional voice functions to voice
connections operating in pulse code modulation at
64 kbps. It can attach a voice server extension (VSE).
voice server extension (VSE). In an Nways Switch, a
module associated with a voice server adapter (VSA) to
supply voice functions to an extended number of PCM
voice connections.
VP. Virtual path.
VPC. Virtual path connection.
VPD. Vital product data.
VPI. Virtual path identifier.
VPN. Virtual private network.
VSA. Voice server adapter (module).
VSEn. Voice server extension type n (module).
WAN. Wide area network.
wide area network (WAN). A network that provides
communication services to a large geographic area. It
can use or provide public communication facilities.
window. On the screen of a station, an area with a
title bar, a menu bar, and scroll bars.
X.25 hunt group. A group of X.25 network interfaces
associated with one common subscriber address. If an
interface is busy, the connection searches (hunts) for
the other interfaces of the group until a free one is
found.
X.25 network interface. A logical resource generated
by the Nways Switch Control Program to provide access
services to a physical X.25 port line. An X.25 network
interface sets up and maintains connections between
calling X.25 subscribers and called subscribers attached
to other Nways Switches.
X.25 Recommendation. An international standard for
the interface between data terminal equipments and
packet-switched networks.
X.25 subscriber. An X.25 end-user connected to an
X.25 network interface through a DTE. A subscriber is
defined by an address and a logical name.
Glossary
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