Case Study

The following case study illustrates a four-node ATM WAN enabling multiple CoS in support of the customer's voice, video, and data applications. Figure 9-6 illustrates an ATM-based network backbone that an NSP might implement. The ATM WAN backbone depicted here is carrying Frame Relay, ATM, and IP traffic.

Figure 9-6. Network Service Provider ATM Backbone Network

The Barker and Brown ATM WAN, illustrated in Figure 9-7, depicts what a customer ATM-based WAN might look like, enabling multiple CoS between several locations. In this scenario, CBR service is being used to carry voice and video traffic from the New York office to Seattle and Paris. VBRnrt service is used to carry corporate intranet services, such as file transfer, between the New York, Seattle, and Sydney offices. UBR service is used between the New York and Seattle/Sydney offices to "fill in" the remaining available bandwidth between these offices, enabling non-mission critical data applications.

Figure 9-7. Barker and Brown ATM WAN