Two TX boards can be configured as a redundant pair. In this configuration, one board is designated as the primary board and the other is designated as the backup. The TCAP task on the backup board is ready to take over the TCAP service if the primary board fails or is taken out of service.
To enable redundancy, the primary and backup TX boards are connected by a private Ethernet connection. The primary TCAP task sends transaction information to the backup TCAP task. This process is known as transaction checkpointing. If the primary board fails or is taken out of service, the backup TCAP task has a complete list of open TCAP transactions so that it can properly handle TCAP traffic.
A TCAP application can control transaction checkpointing by configuring default checkpoint behavior or by specifying checkpoint behavior for each transaction.
The TCAP application must also monitor several new indications that inform the application of the underlying board's state. These indications allow an application to correctly handle board failures, planned outages, and so on.
Refer to the Dialogic® NaturalAccess™ TCAP Layer Developer's Reference Manual for more information.