Hot-standby backup (HSB) is a feature that improves network reliability through redundancy between two devices. After the two devices determine the master and backup roles, the master device forwards service packets and the backup device monitors status of the master device. The master device periodically sends its status information and data to be backed up to the backup device. When the master device fails, the backup device takes over the services immediately.
As users impose higher requirements on network reliability, nonstop transmission has become a key issue, especially on ingress nodes or access nodes of important services, such as Internet access nodes of enterprises and database servers of banks. If only one device is deployed on such a service point, the network is vulnerable to service interruption caused by single-point failures, even if the device is highly reliable.
HSB was introduced to solve this problem. HSB implements service backup between two devices. Service information is backed up in real time through the HSB channel, so that the backup device can take over services without causing service interruption when the master device fails. This technology reduces risks of single-point failures and improves network reliability.