The hmSysGroupCapacity is the number of groups that can
be contained within the chassis. Within each managed
chassis/switch, the groups are uniquely numbered in the
range from 1 to hmSysGroupCapacity.
Some groups may not be present in the chassis, in which
case the actual number of groups present will be less than
hmSysGroupCapacity. The number of groups present will never be
greater than hmSysGroupCapacity.