Failover is when your main connectivity path experiences a problem and the path fails over to an alternate route. In the GateWay, the primary path is usually cellular but could be terrestrial WAN or, in some cases, satellite. The GateWay seamlessly handles the failure using Dejero Smart Blending Technology and omits that problematic path from the blending algorithm.
Failback is the capability to fail back to the original state. Using the GateWay, if the problematic path was to be fixed, Dejero Smart Blending Technology would seamlessly add the path back into the algorithm. The overall quality of the connection would improve.