countdown counter (CC)
In Distributed Queue Dual Bus ( DQDB), each network node has two counters: the Request Counter ( RC) and the Countdown Counter ( CC). While the Request Counter is an up counter for send requests, the Coubtdown Counter is a down counter. The Countdown Counter is loaded with a value and reduced by one step by each ResetSlot. It determines the time slot reserved by the own station on the transmit bus.