Open network control : towards an integrated telecommunications future
Recent advances in the area of computer networking have led to a number of approaches to providing multi-service networks. Of particular importance are B-ISDN & ATM on the one hand, and the Internet, based on IP, on the other. The idea that the coupling of B-ISDN and ATM would provide the global solution for the wide-scale deployment of broadband telecommunications has been strongly challenged by the Internet and its associated protocols. What now exists is a multi-service scenario where distributed multimedia applications with a variety of requirements will be supported across multiple heterogeneous networks, encompassing B-ISDN/ATM and IP as well as other local access and core networking technologies. This thesis introduces Open Network Control as a means to integrate the variety of communication services and platforms that will continue to co-exist. A key starting point is the area of broadband network control, which has seen a number of projects looking at open control mechanisms, using a combination of low-level interfaces onto network devices and the use of middleware technology to provide the control interaction between these devices. In the thesis, the need is argued for a generic level of network control that allows for the support of different network services and different control mechanisms in a uniform and consistent manner. This begins with a critical examination of the approaches to providing multi-service networks that are currently dominant within the networking community, highlighting where each may be claimed as "fit for purpose". A middleware-based Open Network Control architecture and signalling mechanism is then presented, based around a set of strictly defined requirements. Support for continuous media interaction abstractions, a model for the definition of application requirements and a distributed connection binding technique contribute to an overall architecture of Open Network Control. Finally, an evaluation of the architecture is made through a series of measurements based around a real-life application. Performance is considered both in terms of timing characteristics and in terms of the overhead of control messaging within different elements of the architecture.