14.1.1 Next Generation Switch (NGS)

In 1996 BT and MCI embarked upon a joint initiative to design a new switching technique that would be able to integrate both narrow and broadband network topologies. This joint initiative was named 'The Next Generation Switch'. The concept was to produce a network switch that would be modularised, each module performing a different function, as shown in Fig 14.1.

Figure 14.1: NGS architecture.

A number of switches are interconnected across a network, with each switch represented by a vertical row of functions, and performing a different task. The terminology used in this chapter is as follows:

• service control (SC) supplementary services;

• call control (CC) basic call half;

• bearer control (BC) bearer and signal services;

• resource proxy (RP) a 'wrapper' for the resource complex.

This creates three levels of API definition:

• service control call control;

• call control bearer control;

• bearer control resource proxy.

The meetings comprised representation from BT, MCI and a number of well ?known equipment vendors from both the USA and Europe. The idea was to define each module in turn and then define the application programmable interfaces (APIs) that would provide the information flow between the modules. The success of the project foundered on the simplistic view that it would have been possible to build switches using modules from different vendors, with a guarantee that the 'plug and socket' method (API) would provide problem-free working.

There...