Design and implementation of an application server load balancing architecture supporting the end-to-end provisioning of value-added services

Service providers can offer a wide variety of value added services, such as managed home networking, home-automation and security management, multimedia multiparty conferencing and content delivery. Very often hard- and software from different vendors are used to implement these services. In most cases, multiple application servers need to be deployed for each service in order to balance the load of the service sessions. We describe an architecture that offers automatic load balancing of service sessions over the available application servers, abstracting from the actual type of the service and its implementation by translating the service and vendor specific request formats into an internal XML format. The load balancing of the service sessions is done taking into account the capabilities of each application server (which service(s) does it implement), its load, and the location of running sessions (a request to join an active session has to be forwarded to the application server running the session). Furthermore, scalability is ensured by organizing the application servers into pools. New application servers can easily be added.