gtps2m2a | ACF/SNA Data Communications Reference |
You can use the OSTG program to define all of the SNA resources to the TPF
system. See TPF ACF/SNA Network Generation
for more information about the OSTG program.
Once you define SNA resources using the OSTG program, you must load the
resource definitions to the TPF system using the fresh load function or the
dynamic load function. See Loading Resource Definitions by Performing a Fresh Load for more information about the fresh load function.
See Loading Resource Definitions by Performing a Dynamic Load for more information about the dynamic load function.
When you generate the TPF system, you
must use the IODEV macro to define the symbolic device address (SDA) and
system characteristics for each of the following SNA resources that
you define to the TPF system using the OSTG program:
- ALS resources
- CTC resources
- NCP resources.
Otherwise, although you can create the resource definition for the SNA
resource, you cannot activate it.
See TPF System Generation for more information
about the IODEV macro.
The fresh load function replaces the current resource definitions in the
TPF system with an entirely new set of resource definitions. That is,
the resources that were previously defined to the TPF system using the OSTG
program, the ZNDYN ADD command, and dynamic LU support are replaced with the
new resource definitions during a fresh load.
The fresh load function also initializes all of the SNA control block
structures in the TPF system, including the resource vector table (RVT), node
control block (NCB) records, and the subarea address table (SAT).
Therefore, when you perform a fresh load, you must first deactivate
the network because any existing sessions are destroyed.
The fresh load process involves the following:
- When you enter the ZNOPL LOAD command and specify the FRESH parameter, the
new resource definitions are loaded to the current resource resolution table
(RRT) and the old resource definitions are copied to the alternate RRT.
At this point, the new resource definitions are loaded to the TPF system;
however, no processors in the TPF system are using the new definitions
yet.
- As you perform an initial program load (IPL) on each processor in the TPF
system, the SNA control block structures, including the RVT, NCB records, and
SAT, are initialized on that processor. After the IPL has been
completed on a processor, that processor is using the new (or current)
resource definitions.
- The fresh load function destroys all active sessions. Therefore,
you must deactivate the SNA network before you perform a fresh load.
- The fresh load function removes from the TPF system all of the resource
definitions that were created using the ZNDYN ADD command or dynamic LU
support.
- The NCB records and NCB directory records are initialized by the first TPF
processor on which an IPL is performed.
Use the following procedure to perform a fresh load:
- Define the SNA resources using the OSTG program. See TPF ACF/SNA Network Generation for more information about
the OSTG program.
- Load the pilot tape or general data set (GDS) that was created by the OSTG
program to the TPF system.
- Deactivate the active resources in the TPF system. For more
information about deactivating the resources in the TPF system, see Activating and Deactivating Resources.
- Enter the ZNOPL LOAD command and specify the
FRESH parameter to load the new resource definitions to the TPF system.
A message is displayed that prompts you to enter the ZRIPL command.
- Enter the ZRIPL command from each processor in the TPF system to perform
an IPL and incorporate the new resource definitions.
- Note:
- You can enter the ZNOPL STATUS command to
determine the processors that require an IPL to incorporate the new resource
definitions.
See TPF Operations for more information about the
following commands:
- ZNOPL LOAD
- ZNOPL STATUS
- ZRIPL.
Enter the ZNOPL BUILD command if you want to force a fresh load of the
current resource definitions on 1, and only 1, processor during the next
IPL.
The next time you perform an IPL on that processor, the SNA control block
structures in the TPF system, including the resource vector table and the SAT,
are initialized using the resource definitions in the current RRT.
- Note:
- The NCB records are not initialized during the build
function.
See TPF Operations for more information about the
ZNOPL BUILD command.
The dynamic load function allows you to load new resource definitions to
the TPF system without requiring you to perform an IPL or interrupt network
communications. The dynamic load function does not
initialize the SNA control block structures in the TPF system. It
simply updates them with the new resource definitions. Therefore, you
do not need to deactivate the network before you perform a dynamic load and
the existing sessions are not destroyed.
In addition, the dynamic load function does not delete the
resource definitions that were created using the ZNDYN ADD command or dynamic
LU support. These resource definitions remain in the RVT after a
dynamic load is performed.
The dynamic load process involves the following:
- When you enter the ZNOPL LOAD command and
specify the DYNAMIC parameter, the new resource definitions are loaded to the
alternate RRT.
- When you enter the ZNOPL UPDATE command,
the alternate RRT becomes the current RRT, and the current RRT becomes the
alternate RRT. At this point, the new resource definitions are loaded
to the TPF system; however, no processors in the TPF system are using the
new definitions yet.
- As you enter the ZNOPL MERGE command
on each processor in the TPF system, the RVT and its related tables are
updated on that processor with the new resource definitions. After the
online merge
function has been completed on a processor, that processor is now using the
new (or current) resource definitions.
- You cannot delete or redefine local resources using the dynamic load
function. You must perform a fresh load to delete or redefine these
resources.
- You cannot delete or redefine active SNA resources using the dynamic load
function. You must first deactivate those resources. See Activating and Deactivating Resources for more information about activating and deactivating SNA
resources.
- You cannot add ALC terminals using the dynamic load function because ALC
terminals are not defined in the RVT; they are defined in the
WGTA. The same restriction applies to the data terminal equipment (DTE)
that is supported by AX.25 and XALCI LU resources.
Use the following procedure to perform a dynamic load:
- Define the SNA resources using the OSTG program. See TPF ACF/SNA Network Generation for more information about
the OSTG program.
- Load the pilot tape or GDS that was created by the OSTG program to the TPF
system.
- Enter the ZNOPL LOAD command and specify the
DYNAMIC parameter to load the new resource definitions to the alternate
RRT.
A message is displayed that prompts you to enter the ZNOPL UPDATE
command.
- Enter the ZNOPL UPDATE command from one processor
in the complex to switch the current and alternate RRT definitions.
A message is displayed that prompts you to enter the ZNOPL MERGE
command.
- Enter the ZNOPL MERGE command from each processor
in the TPF system to update the RVT with the new resource definitions.
- Note:
- You can enter the ZNOPL STATUS command to
determine the processors where you must enter the ZNOPL MERGE command to
incorporate the new resource definitions.
- If a processor is inactive when you perform a dynamic load,
the RVT is automatically updated with the new resource definitions when you
perform an IPL on that processor. There is no need to enter the ZNOPL
MERGE command once the processor is activated.
- See TPF Operations for more information about
the following commands:
- ZNOPL LOAD
- ZNOPL MERGE
- ZNOPL STATUS
- ZNOPL UPDATE
- ZRIPL.
After you perform a dynamic load, you can use the fallback function to
reload to the TPF system the old resource definitions that were saved in the
alternate RRT, if necessary.
- Note:
- You cannot fall back to the old resource definitions after you perform a
fresh load. Instead, you must reload those resource definitions by
entering the ZNOPL LOAD command.
When you use the fallback function, you can specify whether you want to
reload the old resource definitions using the dynamic load function or the
fresh load function.
You can use the dynamic load function to fall back to the old resource
definitions without interrupting network communications or destroying existing
sessions.
Use the following procedure to fall back to the old resource definitions
using the dynamic load function:
- Enter the ZNOPL FALLBACK command to reload
the old resource definitions from the alternate RRT to the current RRT.
A message is displayed that prompts you to enter the ZNOPL MERGE
command.
- Enter the ZNOPL MERGE command from each processor
in the TPF system to update the RVT with the old resource definitions.
- Note:
- You can enter the ZNOPL STATUS command to
determine the processors where you must enter the ZNOPL MERGE command to
incorporate the old resource definitions.
If you cannot fall back to the old resource definitions using the dynamic
load function, you can fall back to the old resource definitions using the
fresh load function.
Use the following procedure to fall back to the old resource definitions
using the fresh load function:
- Deactivate the active resources in the TPF system. For more
information about deactivating resources in the TPF system, see Activating and Deactivating Resources.
- Enter the ZNOPL FALLBACK command and specify the
FRESH parameter to reload the old resource definitions from the alternate RRT
to the current RRT.
A message is displayed that prompts you to enter the ZRIPL command.
- Enter the ZRIPL command from each processor in the TPF system to perform
an IPL and incorporate the old resource definitions.
- Note:
- You can enter the ZNOPL STATUS command to
determine the processors that require an IPL to pick up the old resource
definitions.
You can use the ZNOPL STATUS command to display
the following information about the RRT, SNA resource definitions, and load
functions:
- Which section in the RRT contains the current resource definitions and
which section in the RRT contains the alternate (or new) resource
definitions.
- Whether the resource definitions in the current and alternate section of
the RRT were loaded to the TPF system using the fresh load function or the
dynamic load function.
- The date and time that the resource definitions were loaded to the TPF
system.
- A description of the resource definitions that were loaded to the TPF
system. This is the description that was specified for the DESC
parameter in the PARM field of the OSTG JCL EXEC statement.
- Whether the update, fallback, and merge functions are enabled or
disabled.
- Whether the build function will be performed during the next IPL.
- A list of all the processors in the loosely coupled TPF system, if these
processors are active, and if they are using the current resource
definitions.
See TPF Operations for more information about the
ZNOPL STATUS command.