Current count, from CMTS initialization, of contention minislots
defined for this upstream logical channel. This count includes
all minislots assigned to a broadcast or multicast SID on the
logical channel.
This is the 64 bit version of docsIfCmtsUpChnlCtrTotalCntnMslots,
and will not be accessible to SNMPv1 managers.
Support for this object is mandatory.