Establishing Active and Standby Roles

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

  • If an Enterprise SBC boots up and is alone in the network, it is automatically the active system. If you then pair a second Enterprise SBC with the first to form an HA node, then the second system to boot up will establish itself as the standby automatically.
  • If both Enterprise SBCs 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 Enterprise SBC with the lowest HA rear interface IPv4 address will become the active Enterprise SBC. The Enterprise SBC with the higher HA rear interface IPv4 address will become the standby Enterprise SBC.
  • If the rear physical link between the two Enterprise SBCs fails during boot up or operation, both will attempt to become the active Enterprise SBC. 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 an Enterprise SBC is functioning properly, its health score is 100.

Generally, the Enterprise SBC with the higher health score is active, and the Enterprise SBC 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 Enterprise SBC might have a health score lower than that of the standby Enterprise SBC, but a switchover will not take place because the active Enterprise SBC'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 Enterprise SBC's health score when they occur. When alarms are cleared, the value is added back to the Enterprise SBC's health score.

You can look at an Enterprise SBC's health score using the ACLI show health command.