ical cornerstones. A network architecture for all types of accesses could look like Figure 3.18, assuming a significant legacy of circuit-mode voice services. Here media gateway controllers are needed in the control layer for the signalling for all the service access types supported. The IP multimedia system could eventually control all services from wherever they are accessed (home, work, visited location) or over whatever access (fixed broadband, digital TV, WCDMA, WLAN etc.). The new architecture is very server rich. See Figure 3.19. The control layer and the ser- vice layer are typically built up by servers. Server overviews are presented in Chapters 8, 9 and 14. 3.6 FUNDAMENTAL PLANS 3.6.1 TARGET - PROBLEM The general goal is to build a network that produces the desired services with sufficient end-to-end QoS and security at lowest cost. This may not sound overwhelmingly diffi- cult. However, in a time of transition there will be many interconnection points between technologies and between actors, both vertically and horizontally. The weakest link will decide the overall quality and security. Understanding Changing Telecommunications - Building a Successful Telecom Business All nodes must be programmed according to required functionality, and obtain the necessary configuration. This work requires some kind of fairly detailed rules. System integration is a key process to get everything to work properly. As mentioned, business views are also important, and over-provisioning may not be an option for economical reasons. Further, all involved parties have a common interest in transforming the network smoothly. Control functions, traffic functions and resources, as well as management functions are concerned. 3.6.2 TOOL The tool, which is used in this book in order to manage successfully the challenging transition, is thus the fundamental technical plan or FP. As seen from Figure 3.20 the FPs are an input to network planning. The boxes with broken/dashed lines are an adaptation in this book to multi-service and mul