Service level routing on the Internet

There is an increasing need for Internet services that can be provided with a high degree of availability and quality of service guarantees. This work presents a backbone architecture for the Internet that supports the notion of a virtual host. Connections to such hosts are directed to a service level router at the border of an autonomous system and routed to an appropriate server host using multiple levels of tunneling. The mechanism routes individual service requests and as a result provides load balancing at finer granularity and shorter response times than existing domain name service (DNS) based load distribution schemes. Once a flow has been identified the service level router may be short-cut by tunneling directly from a (high performance) ingress router. The policy for routing connections to virtual hosts is based on a state update protocol that distributes aggregated resource availability information between the different levels of routing. User-defined routing policies for each virtual host can be incorporated in this mechanism. We give examples of applications that would benefit from our mechanisms, most importantly World Wide Web and multimedia streaming and make a comparison with other current approaches.