Peripheral Component Interconnect (PCI). The PCI Local Bus is a high performance
protocol. (1) A set of semantic and syntactic rules that determines the behavior of functional units in achieving communication. (2) In SNA, the meanings of and the sequencing rules for requests and responses used for managing the network, transferring data, and synchronizing the states of network components. (3) A specification for the format and relative timing of information exchanged between communicating parties.
R
RAM. Random access memory. (A)
RARP. Reverse Address Resolution Protocol.
register. (1) A storage area in a computer’s memory where specific data is stored. (2) A storage device having a specified storage capacity such as bit, byte, or computer word, and usually intended for a special purpose.
remove. (1) To take an attaching device off a network.
(2)To stop an adapter from participating in data passing on a network.
ring segment. A ring segment is any section of a ring that can be isolated (by unplugging connectors) from the rest of the ring. A segment can consist of a single lobe, the cable between access units, or a combination of cables, lobes, and/or access units. See cable segment, LAN segment.
ROM. Read only memory. (A)
S
SCSI. Small computer system interface.
segment. See cable segment, LAN segment, ring segment.
shielded twisted pair. A transmission medium of two twisted conductors with a foil or braid shell.
SMP. System Modification Program
soft error. An intermittent error on a network that causes data to have to be transmitted more than once to be received. A soft error affects the network’s performance but does not, by itself, affect the network’s
overall reliability. If the number of soft errors becomes excessive, reliability is affected. Contrast with hard error.
station. (1) A communication device attached to a network. The term used most often in LANs is an attaching device or workstation. (2) An input or output point of a system that uses telecommunication facilities; for example, one or more systems, computers, terminals, devices, and associated programs at a particular location that can send or receive data over a telecommunication line. See also attaching device, workstation.
STP. See shielded twisted pair.
system. In data processing, a collection of people, machines, and methods organized to accomplish a set of specific functions.
Systems Application Architecture (SAA). An architecture developed by IBM that consists of a set of selected software interfaces, conventions, and protocols, and that serves as a common framework for application development, portability, and use across different IBM hardware systems.
Systems Network Architecture (SNA). The description of the logical structure, formats, protocols, and operational sequences for transmitting information units through, and controlling the configuration and operation of, networks.
Note: The layered structure of SNA allows the ultimate origins and destinations of information, that is, the end users, to be independent of and unaffected by the specific SNA network services and facilities used for information exchange.
T
TCP/IP. Transmission Control Protocol/Internet Protocol. A set of communication protocols that support
telephone twisted pair. One or more twisted pairs of copper wire in the unshielded
threshold. (1) A level, point, or value above which something is true or will take place and below which it is not true or will not take place. (2) In IBM bridge programs, a value set for the maximum number of frames that are not forwarded across a bridge due to errors, before a “threshold exceeded” occurrence is counted and indicated to network management programs. (3) An initial value from which a counter is decremented to zero, or a value to which a counter is incremented or decremented from an initial value. When
Glossary 101