Several indications support TCAP redundancy for TCAP applications. Some of these indications are generated by the TCAP task and are sent to TCAP applications. Others are generated by the Health Management service.
A TCAP application opens the TCAP service and the Health Management service.
Once a TCAP application opens the TCAP service, it receives a run state indication (primary, backup, or standalone) from the TCAP task. If the board state changes (from backup to primary), another run state indication is sent to the application from the TCAP task.
The backup TCAP task sends the backup ready indication only after it reconnects to the primary board or is reloaded. This indication signifies the backup task has a complete copy of the primary TCAP task's open transactions.
The Health Management service provides indications that are useful for monitoring board status.
Ignore the following HM run state indications:
Now primary
Now backup
Now standalone
A TCAP application waits for the run state indication from the TCAP task before modifying its behavior. However, the Health Management service run state indication can be useful as a signal to open the TCAP service after a board loads.
The application closes the TCAP service if any of the following Health Management service indications are received:
Board dead
Board halted
Board loading
Task dead
Stop
The stop indication is only received when a CompactPCI board is removed from its chassis.
The following indications monitor the state of the primary TX board to the backup TX board private Ethernet link:
Connected
Isolated
If an isolated indication is received, active transactions are not being checkpointed.
Note: The indications listed here are not a complete list of the available Health Management service indications, but only those applicable to TCAP applications.