Traffic classification
Typical uses
Typical uses
------------

Packets are classified to be differently processed by the [network scheduler](/wiki/Network_scheduler "Network scheduler"). Upon classifying a traffic flow using a particular protocol, a predetermined policy can be applied to it and other flows to either guarantee a certain quality (as with [VoIP](/wiki/Voice_over_IP "Voice over IP") or media streaming service[SIN 450 Issue 1\.2 May 2007](http://www1c.btwebworld.com/sinet/450v1p2.pdf) Suppliers' Information Note For The BT Network BT Wholesale \- BT IPstream Advanced Services \- End User Speed Control and Downstream Quality of Service \- Service Description) or to provide best\-effort delivery. This may be applied at the [ingress point](/wiki/Ingress_point "Ingress point") (the point at which traffic enters the network, typically an [edge device](/wiki/Edge_device "Edge device")) with a granularity that allows traffic management mechanisms to separate traffic into individual flows and queue, police and shape them differently.Ferguson P., Huston G., Quality of Service: Delivering [QoS](/wiki/Quality_of_service "Quality of service") on the Internet and in Corporate Networks, John Wiley \& Sons, Inc., 1998\. .


What happens if the network scheduler is unable to classify traffic flows?