e to support their set of legacy technologies, CSPs have found themselves forced to use services of large IT integrators with knowledge of a large set of technologies. This is visible in market statistics, which show that only 7% of CSPs' software spending goes to product licenses and ASP while in-house development and IT services take the rest. Also the tendency of large CSPs to use more in-house development and services of large IT service houses is much higher compared to small CSPs, which prefer the use of products from smaller vendors with associated services. There have been various attempts to evolve the vertically integrated, technology- specific OSS/BSS software architecture to a vertically disintegrated, layered architecture, where a single piece of software takes care of the process regardless of the network technology used. Use of single technology-independent systems for customer-related processes (e.g., CRM) has achieved this best with the aid of generic software vendors adapting their horizontal (i.e., industry independent) software for the requirements of CSPs. At the service layer the attempt was P. Tyrväinen known as IMS. Now service delivery platform (SDP) or frameworks (SDF) try to bring together all the interfaces needed for developing a new service in a single, standardized environment. In practice, these SDP/SDF approaches are merely enforcing an engineering practice making such a work easier rather than establish- ing an engineering environment or tool for the automation of new service creation and provisioning. The next approach to standardize interfaces for OSS/BSS software is to stan- dardize the network interface into a single abstraction, which should then be able to interoperate with various wireless and fixed networks with different performance characteristics. The most often cited approach for this is applying all-IP and internet protocols also to wireless mobile communication using new protocols for solving technical problems related to roaming and identity management. The main ch