Modelling and analysis of a buffer in an ATM-based MPLS LER system

We consider the buffer requirement for a shared memory buffer arising in an ingress MPLS (multiprotocol label switching) LER (label edge router) system. The buffer is divided into virtual queues, each of which is assigned to provide a guaranteed IP service. In such a system, strong correlation between the packet interarrival times and the service times exists in each virtual queue since each packet arriving through a link with finite bandwidth is transmitted only after the system receives the entire packet. We provide a framework, including an accurate analytical model and its solution, to compute the queue length distribution for each virtual queue and the total buffer requirement for the shared memory buffer in the MPLS LER system supporting multiple guaranteed IP services simultaneously. Some numerical results on the buffer requirement and the impact of correlation on the performance are considered.