Quality of service challenges in IP networks

IP-based networks play a key role in today's telecommunications. The success of this technology was due, among other factors, to the simplicity and robustness of the Internet Protocol. The price for this simplicity was the best-effort operation of IP networks leading to lack of any quality of service guarantees. As long as the early Internet was used by university professors, students, and others for serving non-profit applications, QoS was not a major issue. However, when Internet became a platform used by carriers and service providers, the lack of QoS could not be neglected. Early attempts to solve the problem, like IntServ and DiffServ, appeared to be much more complex and less scalable than previously assumed. Some relief was given by an impressive growth of available bandwidth in backbone networks, allowing easy overprovisioning. But this solution cannot be used forever. The talk will concentrate on the challenges currently facing designers of large-scale IP-based networks. Limitations of current approaches will be discussed. The concept of overlay networks as a tool to offer a diversified QoS and that of the net neutrality will be presented. A way to offer some QoS guarantees but at the same time keeping the neutrality will be described and discussed.