Load Balancing and Admission Control of a Parlay X Application Server

To increase the number of services and applications in the telecommunication networks a new service architecture has been proposed and specified. The consortia that initiated the new service architecture is called Parlay. Since then, there has been a continued development and 3GPP the standardization group for 3G networks, is now cooperating with Parlay. 3GPP and Parlay are together specifying the Parlay/OSA standard. However, the aim with the new service architecture is to make the art of service development so easy that any software developer should be a potential application developer for telecommunication networks. It is foreseen to be a dramatic increase of new services, but it has been shown that it is still complex to create new applications. Parlay X is a standard which is an extension of Parlay/OSA, initiated to allow access to the telecommunication network capabilities via web services. The Parlay X architectures include an Application Server (AS), which translates the web service calls to Parlay/OSA commands. A typical AS is a distributed environment sensitive to overload. In this paper we propose and investigate an overload control mechanisms for an AS. The methods have been implemented in a real AS to evaluate the performance. Parlay X is a contract driven architecture, where different service providers have different constraints about minimum number of service calls served per second and maximal delays of different services. The methods and algorithms are designed to serve different service providers with different contract parameters