Current count, from CMTS initialization, of contention request
minislots utilized on this upstream logical channel. This count
includes all contention minislots for IUC1 applicable to bursts
that the CMTS correctly received.
This is the 64 bit version of docsIfCmtsUpChnlCtrUsedCntnReqMslots,
and will not be accessible to SNMPv1 managers.
Support for this object is optional. If the object is not supported,
A value of zero is returned.