In the following diagram, SBC1 and SBC2 are two different physical devices that are deployed in an HA mode in different data centers. The endpoints have one connection with SBC1-A, that is Active SBC corresponding to the primary Session Manager, SM1. The second connection is with SBC2-A, Active SBC corresponding to the secondary Session Manager, SM2.

During an SBC1-A fail over, SBC1-S, which is the standby Avaya SBC, handles the media of the active calls. During an SBC2-A fail over, SBC2-S, which is the standby Avaya SBC, handles the media of the active calls.