X25AM Configuration and Management Manual

X25AM Configuration and Management Manual—523424-004
Glossary-1
Glossary
This glossary includes a selection of terms used in this manual.
ABEND. Abnormal termination of a process.
ABM. Asynchronous Balanced Mode. A mode of communications within the ADCCP
protocol whereby two combined stations communicate on a point-to-point link. Either or
both stations can issue commands to set up or dissolve the link. During data
transmission, the stations function as peers. This mode is also used by the HDLC
protocol.
access method. An I/O process that allows applications running on a NonStop NS-series or
NonStop S-series server to communicate with other systems or devices. X25AM is an
access method for X.25 communications.
address. Unique network designation that identifies a device, as described in X.121.
ASCII. American Standard Code for Information Interchange. Standard method of coding
data, consisting of 7 bits for each character plus 1 parity bit.
attribute. In SCF, an attribute is a characteristic that can be specified for an X25AM line or
subdevice. For example, most of the optional network facilities can be specified as
either a line or subdevice attribute, using SCF.
baud. Unit of signaling speed equal to the number of signal events per second. Not
necessarily bits per second (bps).
binary synchronous communications (BSC). Communications protocol using a standard
set of control characters and control character sequences for synchronous
communications.
bit. Binary digit. Smallest unit of information, represented as a 1 or a 0.
block mode. A type of operation in which a device saves characters and attempts to
transmit them only when the ENTER or RETURN key is pressed. The block mode of a
terminal supports page-mode applications. See also conversation mode.
buffer. Area of storage temporarily reserved for performing an input/output (I/O) operation,
into which data is read or from which data is written.
byte. String of 8 bits.
call accepted packet. Packet that a remote entity sends to the network in response to an
incoming call packet, if a circuit can be established.
call clearing. Descriptive phrase for the activities required for disconnecting a virtual circuit.