SNA NRJE Node Managers Guide (30292-90007)

259
P
Physical Unit (PU): A
component of an SNA node. A PU
controls the resources of a node
and reports errors and physical
failures to the SSCP. One PU
exists per node. A PU is the
access method in a host node, the
NCP in the communications
controller node,and the hardware
and software in the peripheral
nodes. PU types for each kind of
node are:
• PU.T1 is a terminal or printer
in an SNA node.
• PU.T2 is a cluster controller,
such as the IBM 3274, in an
SNA node.
• PU.T4 is a communications
controller, such as the IBM
3705, 3720, or 3725.
• PU.T5 is a host processor with
a System Services Control
Point (SSCP).
POWER: See Priority Output
Writers, Execution
processors, and input
Readers.
Priority Output Writers,
Execution processors, and
input Readers: A common IBM
subsystem used to improve the
input and output of jobs to the
VSE operating system
environment.
PU: See Physical Unit.
R
remote: A workstation that is
not local to the host system, and
is configured under the host job
entry subsystem. A remote can be
connected to its host by
communications facilities or by
direct attachment.
remote job access: The
submission of batch jobs to a host
system from remote sites over
communication links
Remote Job Entry (RJE):
Submission of jobs through an
input unit which has access to a
computer through a data
communications link.
Request Header (RH): Control
information that precedes a
request/response unit (RU). It
specifies the type of RU and
contains control information for
the RU.
Request Unit (RU): A message
unit containing control
information, such as a request
code or function management
headers, end-user data, or both.
Response Header (RH):
Control information that
indicates whether a response is
positive or negative. A response
unit optionally follows it.
Response Unit (RU): A
message unit that acknowledges
a request unit. If the response
unit is negative, it will contain