Queuing Delay: Queuing Delay refers to the delay imposed on a cell by its having to be buffered because of unavailability of resources to pass the cell onto the next network function or element. This buffering could be a result of oversubscription of a physical link, or due to a connection of higher priority or tighter service constraints getting the resource of the physical link.
QD
Meaning of QD in English
ATM Forum English vocabulary. Английский словарь организации Форум ATM. 2012