Establishing Active and Standby Roles

Oracle® Enterprise Session Border Controller s establish active and standby roles in the following ways.

• If a Oracle® Enterprise Session Border Controller boots up and is alone in the network, it is automatically the active system. If you then pair a second Oracle® Enterprise Session Border Controller with the first to form an HA node, then the second system to boot up will establish itself as the standby automatically.
• If both Oracle® Enterprise Session Border Controller s in the HA node boot up at the same time, they negotiate with each other for the active role. If both systems have perfect health, then the Oracle® Enterprise Session Border Controller with the lowest HA rear interface IPv4 address will become the active Oracle® Enterprise Session Border Controller . The Oracle® Enterprise Session Border Controller with the higher HA rear interface IPv4 address will become the standby Oracle® Enterprise Session Border Controller .
• If the rear physical link between the two Oracle® Enterprise Session Border Controller s fails during boot up or operation, both will attempt to become the active Oracle® Enterprise Session Border Controller . In this case, processing will not work properly.

Health Score

HA Nodes use health scores to determine their active and standby status. Health scores are based on a 100-point system. When a Oracle® Enterprise Session Border Controller is functioning properly, its health score is 100.

Generally, the Oracle® Enterprise Session Border Controller with the higher health score is active, and the Oracle® Enterprise Session Border Controller with the lower health score is standby. However, the fact that you can configure health score thresholds builds some flexibility into using health scores to determine active and standby roles. This could mean, for example, that the active Oracle® Enterprise Session Border Controller might have a health score lower than that of the standby Oracle® Enterprise Session Border Controller , but a switchover will not take place because the active Oracle® Enterprise Session Border Controller ’s health score is still above the threshold you configured.

Alarms are key in determining health score. Some alarms have specific health score value that are subtracted from the Oracle® Enterprise Session Border Controller ’s health score when they occur. When alarms are cleared, the value is added back to the Oracle® Enterprise Session Border Controller ’s health score.

You can look at a Oracle® Enterprise Session Border Controller ’s health score using the ACLI show health command.