On the impact of traffic control algorithms on resource management in ATM networks

Resource allocation algorithms in ATM networks operate on the basis of the value of certain source traffic descriptors and the extent to which the net work resources are occupied. The different types of algorithms exhibit vary ing degrees of efficiency in estimating the resource to be allocated. Howev er, the values any of them estimate will only be reliable if the traffic de scriptors values remain, throughout the Lifetime of the connections, the sa me as those negotiated in the call set-up phase. This can be guaranteed by a source traffic policing function which forces the traffic of any violatin g sources to respect the values negotiated. Unfortunately, a certain amount of excess traffic escapes the control of real policing mechanisms. This ov erloads the ATM switch for access to the network and consequently may cause an increase in the cell loss ratio. The article estimates the correction r equired by the CAC algorithm to avoid this risk. We compare two different p olicing mechanisms, one based on conventional logic and another on fuzzy lo gic, assessing the influence of their degree of selectivity on the addition al bandwidth the CAC algorithm needs to reserve in order to guarantee the Q oS requirements of all connections. (C) 1999 Elsevier Science B.V. All righ ts reserved.