
Appendix
D
D-1
The Communication Layers' Attributes
This appendix provides information on the communication layer attributes
associated with your OSI coprocessor. It contains the following sections:
Introduction to Attributes
Definition of Default Settings
Frequently Used Acronyms
System–Layer
Attributes
System–Load
Attributes
MMS
Attributes
ACSE (Association Control Service Element)–Layer Attributes
Presentation–Layer
Attributes
Session–Layer
Attributes
Transport–Layer
Attributes
Network–Layer
Attributes
LLC (Logical Link Control)–Layer Counters
MAC (Media Access Control)–Layer Attributes
RS–232 Port Parameters
Each OSI communication layer has attributes (characteristics) that in some
way control or help to control the communication process. There are four
different categories of attributes:
parameters are variables that govern the operation of the module. The
parameters are given a certain value to control the communication
process. There are two basic types of parameters:
- Read–only parameters allow you to view the parameter values.
- Read/write parameters allow you to view and manipulate the
parameter values.
statuses are read–only parameters (associated with the system layer
only).
counters serve simply as a tally of the number of times a certain event
occurs. The counters provide a status of the module’s operation. Some
counters have thresholds, which are flags (or limits) to the number of
times the counter will increment. You are allowed to set some
thresholds, others have pre–determined settings. You can clear most
counters.
actions cause the module to change its state or mode.
Not every layer has all four types of attributes.
Appendix Contents
Introduction to Attributes
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