 bandwidth utilization and minimizes packet loss. Shaping can take originally excessive non-conforming traffic and make it conforming. Traffic shaping is performed at ingress and egress of service provider network. Policing Policing is used for limiting the rate and prevents excessive traffic from congesting the network and assuring that classified traffic conforms to Service level agreements. Traffic policing is performed at ingress to service provider's network. There are three different mechanisms to implement policing: Single bucket, single policer Single rate, three colour Two rate, 3 colour In single bucket, single policer, it allows traffic up to some degree of burst but will discard packets as soon as that burst tolerance exceeded. A simple example is a bucket filling with tap water. The water which can be in bucket will pass as servicing traffic rate while after bucket gets filled with water the water scattered will be discarded traffic . The size of bucket is termed as maximum buffering. In single rate three colour marker, packet marked with green, orange or red based on one rate and two burst sizes. It is used when only burst size matters. In this the packet marked with green colour filled in bucket of committed burst and hence these packets are known as committed information rate. Whereas the packets Downloaded 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 Quality of Service in SDN Technology marked with orange discarded over overflow from first bucket or queue will be in excess burst size bucket and can be used later whereas the packets marked with red are discarded packets. In single rate three colour queue, there is only one source and colour of packets depends on their incoming value when compared with committed information rate(CIR) and peak information rate(PIR) packet marked with green, orange and red based on 2 rates and 2 burst size. It is used when peak rate must be enforced. In this if incoming packets is less than committed information te(CIR) then that packet 