How to encourage cheating with virtual path policing in ATM networks

This paper evaluates the concept of virtual path (VP) policing as an alternative to virtual channel (VC) policing in an Asynchronous Transfer Mode (ATM) network. The Usage Parameter Control (UPC) function includes a peak rate and a sustainable rate policer. Both policers are implemented based on the Leaky Bucket algorithm defined by the ATM Forum. We implement VC and VP policers in parallel in a configuration containing variable bit rate (VBR) traffic VCs multiplexed in a VP. Simulations are used to measure the level of noncompliant traffic declared by the UPC function of both the VC and VP policing units. We evaluate the fairness of VP policing by having one group of VCs generate traffic in excess of their allocated bandwidth. We conclude that VP policing does not protect compliant VCs from non-compliant VCs. In fact, simulation results show that VP policing encourages cheating by penalizing compliant users more than non-compliant users.