A Telecommunications View of the Total Area Network Intelligence is quickness to apprehend as distinct from ability, which is capacity to act wisely on the thing apprehended Alfred North Whitehead We have seen in Chapter 3 that the Integrated Digital Network (IDN) and ISDN evolved from the analogue Public Switched Telephone Network (PSTN). And we have seen as part of this evolution how the network has been logically segregated into a ‘switched information’ subnet (the user-plane or U-plane in ISDN parlance) and a ‘signalling’ subnet (the control-plane or C-plane) | Total Area Networking ATM IP Frame Relay and SMDS Explained. Second Edition John Atkins and Mark Norris Copyright 1995 1999 John Wiley Sons Ltd Print ISBN 0-471-98464-7 Online ISBN 0-470-84153-2 6 A Telecommunications View of the Total Area Network Intelligence is quickness to apprehend as distinct from ability which is capacity to act wisely on the thing apprehended Alfred North Whitehead We have seen in Chapter 3 that the Integrated Digital Network IDN and ISDN evolved from the analogue Public Switcded Teleonone Network PSTN . And we have seen as part of this evolution how the network has been logically segregated into a switched information subnet the user-plane or U-plane in ISDN parlance and a signalling subnet the control-plane or C-plane . In terms of Whitehead s dictum we can associate intelligence with the C-plane and ability with the U-plane. This separation of switching and signalling arises naturally from the essentially different nature of the technologies used for switching and signalling. As we will see the two planes can evolve separately to exploit advances in their respective techniques and technologies. So far this book has focused mainly on the evolution of the user-plane from analogue voice through 64 kbit s circuit switching Frame Relay as an ISDN bearer service and in due course ATM. Each of these switching techniques and technologies provides additional flexibility in the range of services that can be offered to the user and in the way that distance is perceived or preferably not perceived. Remember the overall aim in telecommunications is to take the distance out of information that is Total Area Networking. In this chapter we will look at the part the control-plane plays in Total Area Networking and how it is evolving. 130 A TELECOMMUNICATIONS VIEW OF THE TOTAL AREA NETWORK One of the increasing important factors shaping developments in telecommunications networks and services is competition. The long-heralded liberalisation of .
