Packet scheduling is the means by which data (packet) transmission-governing–a key function of GQOS–is achieved. The Packet Scheduler is the traffic control module that regulates how much data an application (or flow) is allowed, essentially enforcing GQOS parameters that are set for a particular flow. The Packet Scheduler incorporates three mechanisms in its scheduling of packets: A Conformer, the Packet Shaper, and a Sequencer. The Conformer and Sequencer are discussed in more detail when Traffic Control is treated in detail. Since the Packet Scheduler's importance is perhaps essential to overall Traffic Control understanding, it is defined here.
The Packet Scheduler considers the classification provided by the Generic Packet Classifier (GPC), and provides preferential treatment to higher-priority traffic. Consequently, the Packet Scheduler is the first step (in a sequential view) in ensuring that prioritized network transmission of packets begins with data that has been deemed most important.