IBM xSeries 300, Service Manual

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position. When configuring an Nways Switch, the
position parameter indicates the line attachment number
on the LIC module (1 to 8, depending on the LIC type).
potential connection. A predefined connection
through a 2220 network between two HDLC, CES, or
frame-relay devices.
PPP. Point-to-point protocol.
PRA. Primary Rate Access.
private branch exchange (PBX). A switching system
located on a user premises that relays inside lines
(extensions) and provides access to the public
telephone network.
PRS. Primary reference source.
PSDN. Packet switched data network.
PSN. Public switched network.
PSTN. Public switched telephone network.
PTF. Program temporary fix.
PTM. Packet transfer mode.
PTNX. Private telecommunications network exchange.
pulse code modulation (PCM). A standard adopted
for the digitalization of analog voice signals. In PCM,
voice is sampled at a rate of 8 kHz and each sample is
coded in an 8-bit frame.
PVC. Permanent virtual circuit.
Q signaling (QSIG). An international standard for
signaling procedures in private telecommunication
networks. It applies to the PBX-to-Nways Switch
interface, which is called the Q reference point.
QoS. Quality of service.
QSIG. Q signaling.
quality of service (QoS). In a 2220 network, a set of
parameters that guarantees the characteristics of a
connection, mainly its end-to-end delay, delay variation,
and packet loss tolerance.
RABM. Router and Bridge Manager.
rack. A metallic structure, with a standard 19-inch
width, that houses the hardware elements of an Nways
Switch, that is, logic subrack with modules, fan boxes,
and power units.
When configuring an Nways Switch, the rack parameter
indicates the 2220 Model (rack A is the Model 300 or
500, and rack B is the Model 501).
RDI. Remote defect indication.
real-time processing. Refers to the manipulations of
data that are required, or generated, by certain process
while the process is in operation. Usually, the results
influence the process and, perhaps, related processes.
remote user console. A station running OS/2, TCP/IP,
and Nways Switch Resource Control. It can be
connected to the NAS of an Nways Switch to remotely
control and service it.
resource. In an Nways Switch, a hardware element or
a logical entity created by the Control Program.
Adapters, modules, and line attachments are examples
of physical resources. Control points, logical trunks,
logical ports, and network interfaces are examples of
logical resources.
resource profile. A record of the characteristics of an
Nways Switch resource. It includes (for example) the
part number or module name, the change level, and the
name and phone number of the person to contact when
a problem occurs.
RETAIN. Remote Technical Assistance Information
Network
RIP. Route Information Protocol.
router. An attaching device that connects two LAN
segments of the same or different architectures. It can
also be connected to a wide area network. A router
works at the network level (layer 3) of the OSI reference
model by determining the best paths for network traffic
flows.
Router And Bridge Manager. An application that
provides distributed management for routers such as
the IBM 2210 or 2216, bridges such as the IBM 8229,
and communication controllers such as the IBM 3746 in
IP mode.
RS. Recommended specification.
RSF. Remote support facility.
RSN. Receive sequence number.
RT. Real-time.
RVX. RS/EIA-232, V.24/V.35, X.21.
s. Second.
SCR. Sustainable cell rate.
SDH. Synchronous digital hierarchy.
SDLC. Synchronous data link control.
SDT. Structured data transfer.
serial line internet protocol (SLIP). A TCP/IP
protocol used on a point-to-point connection between
Glossary
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