IP core network, overlay network and communication service (4) : Unneeded virtual network operator, Virtual ISP network and Improving structure of NGN

摘要

Until now, we have reported "service-over-core network" as a communication network framework that enables the provision of virtual networks for building communication services, and communication resource management, priority controls, core network function, a method on how each service changes structure of its virtual network, and so on. We newly discuss why the activities performed by virtual network operators in designing and providing virtual networks actually degrades the reliability of the communication network system, and increases communication cost, and so on. Next, we describe how to implement virtual ISP networks, in which a P2P service, mail and Web service etc, can be offered. We consider how to build fixed and mobile telephony services. We revise the NGN structure by replacing the transport stratum of NGN with a new core neiwork whose functionalities include those of the service-over-core network, then place both NGN's service stratum and other communication services on the new core network. We think that revised NGN will offer both virtual networks for building IP-based communication services and IP circuit interfaces for IP terminals, so that the application range of NGN will be significantly widened.