ice layer, management enablers Adaptations AAA, encryption middleware Clients, (WEB services) Servers, Control Tunneling Charging IPsec Service Session Mobility control management Dimensioning Signaling Economy DNSSec Security Numbering Switching and impact Availability service also on routing (control and manage- ment side Synchronization connectivity Connectivity resources) Network resources management Traffic Transmission Frequency (inclecho Canc Organisation Figure 3.27 A new look at the fundamental plans Understanding Changing Telecommunications - Building a Successful Telecom Business Many plans have security features, because of threats such as attacks on numbering and routing as described in the Chapter 6. Also the management side must be protected (compare Figure 6.10). Cost elements are related to the functional content. An optimal solution offers an acceptable service at lowest cost. In Chapter 5 the expression 'Economy of service' is introduced. This service production view is further developed in Chapter 8 for a packet production assembly line. Finally there is a need for an interconnection plan. Such plan is very similar to a set of fundamental technical plans. Critical interconnection issues, at least for fixed opera- tors, are: Point of interconnect (POI) Services Subscriber access Number portability Charges and payments Billing Numbering Signalling and interface standards Routing principles (e.g. emergency) Synchronization Installation, operation and maintenance QoS and security Service level agreements The interconnect area is treated in more detail in Chapter 15. Another kind of interconnect is represented by cooperating technologies, such as UMTS and WLAN. Three possible relations are shown in Figure 3.29. Tight interworking means Other functionality provided by solutions Mobility management based on IETF protocols Subscriber management Tight interworking Billing/Charging Loose interworking Security management UMTS core NetworkSe Mobile IP for Internet roaming "No interworking" Figure 3.28 Tec