The attackers must attack a series of 5 generators, however only 1 of these needs to be down to have access to the switch. The generators are set up so you must advance and hold the inside of the base.
The Defenders main goal is to keep repairing the generators and protect the 'Switch ForceField Generator' as long as possible.
Team work is a 'must have' in this map. Otherwise people might say "this map is impossible" and blow it off just because they can't cap it souly by themselves.