Gateway-based call admission in distributed object oriented systems

Many applications in telecommunications will depend on distributed systems to provide enough capacity. In a distributed system a service is split up into a number of modules (often called objects) that can be placed at different nodes or processors in a network. A service can be seen as a number of invocations of the objects in a certain order. There are a number of performance problems which have to be solved. How shall objects be distributed on the nodes? How shall the load be distributed among the nodes for a given object distribution? How shall the distributed system be protected from temporary overload situations? In our paper we investigate these questions for distributed systems where requests for service arrive to a gateway from which they distributed to the nodes of the system. We assume that the object distribution is given and we concentrate on protecting the system using three different external load control mechanisms: Percent Thinning, Call Gapping and Tokens. Using simulations, we nd that Tokens provide the best system protection