o conform to some specified behaviour. This is usu- ally a worst case or a worst-plus-average case. For example, the worst case allowable might be 100 Mbps of data for a maximum of 2 seconds and the average allowed over any seconds might be 50 Mbps. Traffic shaping is about regulating data transmission - both the average rate and the intensity of bursts ("burstiness"). The most obvious use of traffic shaping is to reduce congestion, and it can be used ultimately to allow a carrier to achieve QoS goals and SLA requirements. This can be critical where ser- vices that are promised include real-time applications such as audio and video. 13.5.1 Traffic-shaping Methods Traffic shaping is where the rate of traffic flow is adjusted or optimised to ensure quality parameters are satisfied within the limitations of the telecom network. 13 Traffic Management Examples of traffic-shaping methods include: reducing the peak cell rate limiting burst lengths reducing peak-to-peak CDV by appropriately spacing cells in time queue service schema. Given some switches that are connected together, along with a signalling archi- tecture that enables people to make calls, the problem is how to deliver the promised QoS. This requires a resource management strategy, since congestion is the greatest factor in data loss. Of course, costs need to be kept sufficiently low so that a profit can be made from the charging scheme in place. The most important traffic param- eters proposed for resource management are mean bitrate, peak bitrate, variance bitrate, burst length, burst frequency, cell-loss rate and cell-loss priority. These parameters are considered in three states: their actual values, their measured values and their effective values as experienced by the customer. The functions involved in traffic shaping are: 1. Acceptance Function: Each switch can accept a virtual circuit request based on the traffic parameters declared by the customer. Acceptance is given if the resulting traffic mix will not cause the switch to fail in order to achi