Overview
The device's High Availability (HA) feature provides 1+1 system redundancy using two devices. If failure occurs in the active device, a switchover occurs to the redundant device which takes over the call handling process. Thus the continuity of call services is ensured. All active calls (signaling and media) are maintained upon switchover.
| ● | Only IP calls are maintained during a switchover; PSTN calls are dropped (by sending a SIP BYE message to the IP side). This is because only the active device is physically connected to the PSTN interfaces (e.g., E1/T1). For more information, see Device Switchover upon Failure. |
| ● | HA is supported only on Mediant 800 Media Gateway & Enterprise Session Border Controller H/W Rev. B and C. |
The figure below illustrates the Active-Redundant HA devices under normal operation. Communication between the two devices is through a Maintenance interface, having a unique IP address for each device. The devices have identical software and configuration including network interfaces (i.e., OAMP, Control, and Media), and have identical local-port cabling of these interfaces.
