Both sides go at the same time. After the dump in and breakout, both defensemen play 1 on 2 against the other line's forwards. 1. 2 two forwards swing low and receive a pass from the coach, then step over center line and dump in cross ice. 2. Goalie stops the puck for the defenseman, who initiates a strong side breakout, then comes out to plays 1 on 2 against forwards from the other line. 3. Forwards attack 2 on 1 against the defenseman from the other line.

1 on 1 2 on 1 Breakout

Credit to Weiss Tech.