TABLE OF CONTENTS The PSTN has been around for a long time and its performance is well understood. The technology is mature and the issues regarding the management of the network are, for the most part, also well understood. We can see this in the excellent performance and network availability delivered by the PSTN a record that is to be envied by some younger network technologies.
The world does not stand still, however, and the loads placed on the PSTN change, together with our expectations of what the network could deliver. Many facilities have been added to the network without disruption to the network capacity, such as the 1471 service, but other services have stressed the network such that great ingenuity is required to manage them and their impact on other traffic. A classic example of this is the televote, a modern phenomenon capable of generating enormous numbers of call attempts to a small number of destinations, over very short time-scales. Offering such services must be done without causing an adverse effect to existing services and traffic that share the network. So, as the number of heterogeneous traffic streams carried by the network grows, there is greater need to study how different types of traffic stream interact with each other as they compete for the same infrastructure.
This chapter considers IP-dial traffic, i.e. customers using their computers to access the Internet by connecting across the PSTN to their Internet service providers (ISPs), using analogue modems or ISDN...
