 mechanisms in order to The Next-Generation Network Infrastructure Customer Edge Network Softswitch Next-Generation Class 5 Switch SS7 Signaling Class 5 Dialup Modems Network Switch Fiber Trunking Wireless Gateway DSL Modem Remote Access Concentrator Multiservice Cable Modem Optical Backbone OC-3/ OC-12 Frame Relay Broadband Access Switch IP/MPLS Service Management Functions: Billing/accounting Service-level def SLA management Provisioning Subscriber management Troubleshooting Figure 10.8 The next-generation network edge deliver the requested performance and thereby live up to the SLAs. One of the major benefits is that it allows rapid and dynamic service provisioning, and it even allows customization for individual users. These service changes can be made without affecting the core, so as new service logic is required and as market seg- ments find demand for new services, we will not necessarily have to reengineer the entire core network to accommodate those changes. Service provisioning is there- fore decoupled from service specification and service delivery. The Inner Tier: The High-Speed Core The access and edge switches are designed to be scalable, both in port counts and in their ability to deliver multiservice sup- port, and they are evolving to include more and more intelligence and features that would enable policy-based service management. In contrast, core switches are Chapter 10 Next-Generation Networks designed to be incredibly big and incredibly fast but generally quite dumb. Their main objective is to transport traffic as reliably and quickly as possible, at the high- est available rate. So in the emerging environment, we see a reversal. In the traditional PSTN, the edges served the network core, and the network core had all the intelligence. Now, the network core is serving the edges, and intelligence is being distributed closer and closer to the customer premises (see Figure 10.9). The Multiservice Intelligent Edge As discussed in the preceding section, the evolution of a multiservice intelligent