This counts CCMs this specific MEP has received from its remote peer MEP or MEPs in the same maintenance association, the number that ultimately drives that MEP's continuity and fault state, since a MEP declares its remote peer down after missing roughly three and a half CCM intervals' worth of these. Watching this counter's rate for one particular MEP is the most direct way to catch an impending Loss-Of-Continuity alarm before it fires, since the increment rate visibly slowing precedes the actual state change. If this counter for MEP 5 stops incrementing entirely for more than 3 CCM intervals, that MEP is about to, or already has, flagged its remote peer as down.