Definition

Next-generation, service-capable networks are defined as networks that are capable of differentiating between subscribers and subscriber sessions and of understanding application requirements over the network. In comparison to the public Internet, where all traffic competes for resources with equal priority and without control structure, next-generation networks segregate traffic types, users sessions, or individual users into defined access channels. Subscriber sessions may continue onto the public Internet, where traffic returns to a best-effort format, but sessions that remain within the carriers’ sphere of control maintain an explicit network and service contract. The most condensed definition of the next-generation, service-capable network is "control."

Overview

This tutorial will focus on digital subscriber line (DSL) access using asynchronous transfer mode (ATM) permanent virtual circuits (PVCs) as the underlying transport mechanism for ATM–native and Internet protocol (IP) sessions (see Figure 1).

Figure 1. DSL Using ATM PVCs