Hierarchies for Network Evolution

The success of the Internet is due to best-efforts delivery which allows for easy expansion, coupled with a congestion-adaptive reliable transport protocol (TCP), which serves well for the delay-insensitive traffic of Web browsing or file transfer. There are several new proposals for handling Quality of Service (QoS) for real-time and multimedia traffic, but their introduction is slow. The scale of the Internet is one of the impediments to successful QoS provision. Hierarchical structure is the key to scaling problems, but it must be provided in a way that helps evolution too. This paper reports work in progress on techniques for organising hierarchies using clustering, which could be applied to clouds of QoS capable routers or to support multicast applications.