Buffer overflow estimation in network elements, multiplexing independent regulated inputs [packet switched networks]

The estimation of resource usage in network nodes is a basic issue from the point of QoS (quality of service) provisioning. This paper is about estimating the buffer overflow within network elements, which are represented by a service curve property. There are some previous investigations which define bounds on buffer overflow for such elements, multiplexing homogeneous and heterogeneous independent regulated inputs. The main topic of this paper is setting up new bounds for the heterogeneous case, by using a new PGF (probability generating function) approximation presented in (J. Biro et al, Proc. of 1st Int. Work. Conf. on Performance Modelling and Eval. of Heterogeneous Networks, 2003). We show, that the new bounds are also valid for the homogeneous case, so the results for the homogeneous and the heterogeneous case can be integrated into a single formula. It is also shown, that the new bounds improve the existing ones in most cases.