OSI/TS Configuration and Management Manual

Configuring the OSI/TS Subsystem
OSI/TS Configuration and Management Manual—424831-001
3-10
Capacity
•
The interactions of the OSI/TS subsystem with applications and the operating
system
•
The physical layout and attributes of the subnetwork being used
•
The meaning of the system generation program (SYSGEN) and subdevice
configuration attributes
Capacity
If a TSP process is running in a high-performance-class CPU (such as a Cyclone), the
maximum number of subdevices that can be configured is 1024. For all other CPU
types, the maximum number of subdevices is 512. You can take advantage of the high
number of subdevices allowable to configure different sets of subdevices for use as
alternative or backup configurations.
The same limits apply to the maximum number of transport connections for TSP
processes. This maximum is configured by the startup parameter
TSP^MAXCONNECTIONS and the SCF PROCESS attribute MAXCONNECTIONS.
However, the actual number of concurrent transport connections that a single TSP
process can support is determined by a number of factors, such as:
•
Traffic patterns of the transport connections
•
TPDU size (SCF SU attribute TPDUSIZE)
•
Credit window (SCF SU attribute L4WINDOW)
•
Multiplexing in transport classes 2, 3, and 4 over X.25 networks
•
Buffer pool size (startup parameter TSP^BUFFERPOOLPAGES)
•
I/O size of the application (startup parameter TSP^RECEIVESIZE and SCF
PROCESS attribute RECEIVESIZE)
•
Number of outstanding READ requests posted from the application on
each of the subdevices
•
Network response time required to support the application
Default Attribute Values
When initially configuring your subsystem, it is probably easiest to use the default
values provided by Compaq, unless other information or special requirements indicate
different values. At the least, the default values help to get the system up and running
quickly. Then, armed with detailed knowledge about the applications using your
OSI/TS subsystem, you can monitor the system and take corrective action as needed.
Note. Default values are not advisable for attributes such as timeout values on networks using
low-speed communications lines, or timeout values where heavy traffic volumes are
anticipated. In these cases, the attribute values should be calculated as carefully as possible.