2004 IRISH SCIENTIST YEAR BOOK

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Institute of Technology Carlow
David Denieffe
Letting the user decide

Brian Carrig, postgraduate student at IT Carlow, who is part of the Network Research Group

The M2NRG (Multimedia Multiservice Networks Research Group) is a recently formed research team within the Computing and Networking Department of IT Carlow. Its team members include a number of lecturers and postgraduate students. The Research Group is primarily concerned with investigating and developing networks for the provision of multimedia and multi-services, with the current research focus in the area of user-centric Quality of Service (QoS), and securing and authentication of real-time converged traffic.

Computer data networks, such as those built using the Internet Protocol (IP), provide 'best-effort' delivery. This is somewhat analogous to the modern postal system, where no guarantees are provided on the route letters will take, the order in which they will be delivered, the time by which they will be delivered, or even if they will reach their destination at all. However, for the most part, this method has been satisfactory, allowing engineers to build very simplified networks, leading to the enormous popularity of the Internet today.

Next Generation Networks (NGNs) describe a concept as opposed to a complete technological architecture, where intelligent edge devices are attached to a high-speed multi-service core, allowing for the convergence of many existing networks into one new network supporting all forms of voice, video and data traffic. While the modern Internet, with its almost ubiquitous presence, is perceived as a natural platform for building NGNs, in reality this has been slow to materialise. The primary reason for this relates to the deficiencies inherent in the best-effort service model. Real-time applications all require strict upper bounds on QoS measures such as delay, jitter (inter-arrival delay), packet loss and corruption.

The Internet Engineering Task Force (IETF) approaches to QoS are the Integrated Services (IntServ) and the Differentiated Services (DiffServ) models. Both of these models have been widely covered in academia, but as yet have not been offered on a commercial basis to end-users. This may be due to both the complexity of their deployment, as well as confusion over possible billing structures. Much of this research is focused on mapping particular traffic and application types to specific service levels. We feel, however, that this approach is inherently flawed � ignoring as it does any input from the user on the desired QoS level.

Our approach, called Variable Demand Provisioning (VDP), offers a more user-focused model, where the customer rather than the network service provider will choose the desired level of service. While this should help stimulate demand and pave the way for the deployment of exciting new services, it presents a number of difficulties in relation to network provisioning. For this reason, we seek to assess the impact of VDP on current and future network architectures.

Contact: David Denieffe, Department of Computing & Networking, Institute of Technology Carlow;
Tel: 059-9170400; E-mail: [email protected]