ATM QoS Priority Scheme

Each service category in ATM has its own queue. There are mainly two schemes for queue service. In round-robin scheme, all queues have the same priority and therefore have the same chance of being serviced. The link’s bandwidth is equally divided amongst the queues being serviced. Another scheme is weighted round-robin scheme, which is somehow similar to WFQ in IP networks: queues are serviced depending on the weights assigned to them. Weights are determined according to the Minimum Guaranteed Bandwidth attribute of each queue parameter in each ATM switch. This scheme ensures that the guaranteed bandwidth is reserved for important application such as CBR service category.