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How failover works

ElfiqSince the Internet has become critical for most organizations to conduct daily activities, losing Internet access is unacceptable for any period of time. Link Balancers are a key tool for preventing such disruptions as they ensure that Internet connectivity is maintained even when an ISP is currently unavailable because multiple ISPs are used concurrently.

Link Balancers will perform the failover process in this fashion:

  • The Link Balancer checks the status of each ISP link to validate its health; these checks occur every few seconds. These checks are done outside the carrier's network at predetermined sites, which are known for their availability, such as search engines.
  • When a link stops responding to the tests conducted by the Link Balancer, the link is taken off the list of available links.
  • The Link Balancer transfers traffic to the available link(s) installed with the Link Balancer.
  • The Link Balancer continues to test the unavailable link, and when it returns to being usable with acceptable metrics, it is returned to the list of available links.