5.2.1 Traffic Classification and Conditioning

On entering a Diffserv domain, a flow may be conditioned and is then mapped to a BA, in accordance with the traffic classification policy stated in Service Level Agreement (SLA). This classification may be based on the DSCP only, in which case the classifier is called BA classifier or may be based on a combination of one or more header fields, and is hence named Multi Field (MF) classifier.

After classification, a flow is passed through traffic conditioner. Typically, traffic conditioners have the following components [8]:

Fig. 5.1 Classifier and Conditioner [8]

Meter: Metering involves measuring the temporal properties of flows and providing differential treatment to in-profile and out-of-profile profile flows by triggering an action for the packet.

Marker: Markers set the DSCP value, either independently or according to the state of the meter. Markers may also change the DSCP value of the packets, which is termed as re-marking.

Shaper/Dropper: A Shaper shapes the flows by buffering and/or dropping some packets, to bring the flow in conformance with the SLA. Dropper is a special case of a shaper, with buffer size zero.