Two part question:
What is the most goals scored in one period in the NHL by one team?
What is the most combined goals scored in one period in the NHL?
Most goals, one team, one period
9 – Buffalo Sabres, Mar. 19, 1981, at Buffalo, 2nd period (during 14-4 win over Toronto)
Most goals, both teams, one period
12 – Buffalo Sabres, Toronto Maple Leafs, at Buffalo, Mar. 19, 1981,
(2nd period, Buffalo scored 9 goals, Toronto 3. Buffalo won 14-4)
12 – Edmonton Oilers, Chicago Blackhawks , at Chicago, Dec. 11, 1985,
(2nd period, Edmonton scored 6 goals, Chicago 6, Edmonton won 12-9)