IPQoS includes the following modules, which are part of the Diffserv architecture that is defined in RFC 2475:
Classifier
Meter
Marker
IPQoS adds the following enhancements to the Diffserv model:
Flow-accounting module
802.1D datagram marker
This section introduces the Diffserv modules as they are used by IPQoS. For detailed information about each module, refer to IPQoS Architecture and the Diffserv Model.