Ps has developed during the two last decades from a focus on loudness (transmission quality) in analogue PSTN networks to a focus on security and QoS for real-time services in IP networks, with call control servers, policy servers and application servers. That is why this book contains dedicated chapters on these subjects. Charging is another important area. This subject is covered in the Chapter 5, Section 5.11. The new systems for horizontal networks will be rolled out in many states of revision. In order to be somewhat independent of the various implementation steps, a layered model is preferable. In such a model the particular node implementations are less important. Since FPs are normally seen end to end they fit excellently into layered models. 3.6.4 FP VERSUS PTP PTP stands for particular (fundamental) technical plans. The particular characteristics are based on the capabilities of a specified supplier solution and related network design. Thus they describe supplier-specific network design capabilities using operator language. Such plans could be used widely, starting with a statement of compliance to operator specifications. Network integration is another process supported by PTP. The PTPs can accompany a procurement from tender to ready for service, enabling a consistent process for a particular contract. 'What is ordered should also be delivered' Historically, the local exchange has been the main network element for the use of PTP at Ericsson. Later on the concept was adopted for other network solutions. With PTP it is also easier and faster to respond to an operator specification, particularly regarding the statement of compliance. 3.6.5 CONVERGING FP To a large extent the ongoing convergence is in fact a convergence between FPs. See Figure 3.22. 3.6.6 CONVERGING TELECOM, DATACOM AND MEDIA INDUSTRIES In principle three worlds collide: the telecom world, IP world and media world. To make the converged multimedia world work well there is a need for a kind of glue or mid- dleware. See Figure 3.23. This re