CDV

In asynchronous transfer mode (ATM), the variation in actual cell transfer delay (CTD) and the expected transfer delay of an individual cell. CTV is a form of jitter, which can seriously degrade the quality of voice and video payloads. If cells arrive sooner than expected, the clumping can cause the peak cell rate (PCR) to be exceeded, and the excess cells to be discarded. If some cells arrive too late, the result may be gaps in the received information stream. Cell delay variation tolerance (CDVT) is a measurement of the maximum allowable CDV tolerance between two end stations. Peak-topeak CDV is negotiated between the end station and the network, with peak-to-peak referring to the best case compared with the worst case, i.e., the difference between the earliest and the latest arriving cells on a connection. See also ATM, cell, CTD, jitter, payload, and PCR.