SNAX/HLS Diagnosis and Support Manual

Glossary
104706 Tandem Computers Incorporated Glossary–1
This glossary defines terms used and referred to in SNA and SNAX/HLS. Several
definitions have been borrowed from IBM’s Dictionary of Computing (SC20-1699) and
IBM’s Network Program Products: General Information (GC30-3350).
$SSCP. Process name of the SNAX/XF Service Manager.
ANSI. American National Standards Institute.
application prototyping and simulation. A SNAX/HLS tool used by software developers to
quickly and easily determine how their applications work.
APS. See application prototyping and simulation.
BCPU. Backup central processing unit.
BIS. Bracket Initiation Stopped.
BIU. Basic information unit.
brackets. The SNA concept relating to logical units of work, frequently associated with
transactions. Brackets are not used on all sessions. When used, one partner is known
as the “first speaker” and the other as the “bidder.” The distinction is set at session–
establishment. SNAX/HLS uses the Bracket State Manager rules appropriate to the
half session.
CAU. See channel adapter unit.
CCITT. Comite Consultatif International Telegraphique et Telephonique (International
Telegraph and Telephone Consultative Committee).
channel adapter unit (CAU). A hardware unit that, together with the SNAXLink software
and the CIU, provides a direct channel link between a Tandem system and an IBM
system. The CAU connects to the IBM I/O channel cables and to the CIU controller
using fiber–optic cables.
channel status word (CSW). An area in storage that provides information about the
termination of I/O operations.
CIU. See communication interface unit.
cluster controller. A device that controls access (I/O operations) to a group of terminals
or printers connected to it. A cluster controller may be controlled by a program stored
and executed in the unit, or it may be entirely controlled by hardware.
CMI. See Communications Management Interface.
communication controller. A device that directs the transmission of data over the data
links of a network; its operation may be controlled by a program executed in a
processor to which the controller is connected, or it may be controlled by a program
executed within the device.