IBM 5500-01E, Руководство по эксплуатации, установке и обслуживанию

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Glossary 183
requests and responses used for managing a network,
transferring data, and synchronizing the states of net-
work components.
R
random access memory (RAM) A computer’s or
adapter’s volatile storage area into which data may be
entered and retrieved in a nonsequential manner.
read-only memory (ROM) A computer’s or adapter’s
storage area whose contents cannot be modified by the
user except under special circumstances.
router An attaching device that connects two LAN seg-
ments, which use similar or different architectures, at
the reference model network layer.
The topmost device in a hierarchical network. (A 2480
access point configured as a router.)
routing Forwarding a message unit along a path through
a network as determined by parameters carried in the
message unit.
S
serial line Internet Protocol (SLIP) A protocol used to
run the Internet Protocol (IP) over serial lines, such as
telephone circuits or RS-232 cables, interconnecting
two systems.
segmentation Dividing a data unit into shorter pieces to
fit the buffer size of nodes that store and forward data.
Simple Network Management Protocol (SNMP) In
the Internet suite of protocols, a network management
protocol that is used to monitor routers and attached net-
works. SNMP is an application layer protocol. Informa-
tion on devices managed is defined and stored in the
application's Management Information Base (MIB).
socks protocol A protocol that enables an application in
a secure network to communicate through a firewall via
a socks server.
star A centralized network topology in which all work-
stations are individually connected to a single controller.
T
topology The logical or physical placement of nodes.
Transmission Control Protocol/Internet Protocol
(TCP/IP)
A set of communications protocols that support peer-to-
peer connectivity functions for both local and wide area
networks.
transmission control character A control character
used to control or facilitate transmission of data between
data terminal equipment.
twinaxial cable (1) A cable consisting of two conduc-
tors, usually small copper tubes or wires insulated from
each other, within and insulated from another conductor
of larger diameter, usually copper tubing or copper
braid. (2) A cable made of two twisted wires inside a
shield.
W
wide area network (1) A network that provides com-
munication services to a geographical area network, and
that may use or provide public areas larger than that
served by a local area network or a metropolitan area
network, and that may use or provide public communi-
cation facilities.
(2) A data communication network designed to serve an
area of hundreds or thousands of miles; for example,
public and private packet-switching networks, and
national telephone networks
Wire fault An error condition caused by a break or a
short circuit in the cable segment that connects the
adapter port to its access unit, such as an IBM 8230
Token-Ring Network Controlled Access Unit.