ple of a service network structure. Applications, management and service enablers are main functions of the server-rich service network. Everything is connected by means of an IP infrastructure backbone network networks provide and support end-user services, support partner cooperation, B2B, B2C, provide service management, end-user management and core network access. The owner of a public service network may be a mobile operator, an ISP, a portal or a virtual network operator (VNO). In the enterprise segment, the mobile VNO or systems integrator may take on important roles. The word 'enabler' should be borne in mind, with location as a good example. Enablers are the main tools for the service network, creating value beyond voice. Semantically, also the often-used term 'middleware' has a flavour of enabler, by offering API, service handling and end-to-end protocols (e.g. XML) to the applications. The service layer can also be regarded as a promoter of business contacts via telecom on behalf of direct contacts or contacts via other media. It participates in the contacts as an enhancing middleman. Many presentations do not show the traffic flow between the server in the service network and the client. Such flow has been included in the reference model, and also a hint regarding the interaction between service network and terminals. In fact, there are strong dependencies between the terminals and the service network, creating needs of combined application development. Figure 9.3 gives an example of the server-rich structure of the service network and also the traffic flow referred to above. Understanding Changing Telecommunications - Building a Successful Telecom Business Content & application Telecom business provider Operations Back-end Content = $$ systems User support Application support Business support General Application Management Authentication, (CAS) framework support authorization Provisioning, Common billing, SCS, service enablers directory CRM, etc. Provisioning center Enablers Deployment Operation and 