is transferring data of lower priority queue, network OS will hold data of the lower priority queue and process data in higher priority queue first. The network OS does not care how long lower priority queues have to wait for their turn because it always finishes each queue from highest to lowest priority first before moving to the next queue. Within each queue, packets are forwarded based on First-In-First-Out basis. Custom queue (CQ) Custom queue is divided into 17 different sub queues. The first queue, queue 0, is reserved for the network OS to transmit system packet, the other 16 queues are for user-defined packets. User can define various important packets and assign them into each queue. Each queue has limited size and it will drop all coming packets if it reaches that limit. Each queue is serviced based on how much packets are served in each queue. If that limit is met, the network OS will hold packets of current queue and services the next queue until that queue is empty or it reaches its packet limit. If one queue is empty, the network OS will skip that queue and service the next queue. See also Message queue References Operating System Scheduling Operating System - Scheduling OS Scheduling and Buffering Computing terminology Queueing theory