Classes
Queuing disciplines and classes are closely tied to each other.
Each class “owns” a queue.
Classes are identified by two methods
- Class ID - which is assigned by the user. This ID is structured. The major number of the class is equal to the major number of the queuing discipline “owned” by the class, while the minor number identifies the class in the queuing discipline.
- Internal ID - which is assigned by the queuing discipline. This is used for reference within the kernel.
Class IDs are structured like queuing discipline IDs. Major Number corresponds to the instance of the queuing discipline, and minor number identifies the class within that instance.
Flexibility: Classes don’t store the packets themselves - they may have other queuing disciplines to take care of that - and this queuing discipline may have classes and so on.