Bandwidth allocation and call admission control in high-speed networks

The authors discuss the broad issue of bandwidth allocation and call admission control (CAC) in high-speed networks, focusing on asynchronous transfer mode technology. It is maintained that despite the considerable amount of high-quality work carried out in this area, the debate surrounding these issues is not yet resolved. The complexity of dealing with a wide variety of as yet unknown user traffic types, as well as the evolving architecture of networks, means that currently proposed solutions are only an intermediate step of the design process. The authors discuss the nature of user traffic and illustrate how it can impact the debate on the quality of service, concentrating on some "equivalent bandwidth" type CAC strategies. Also discussed is a method which uses diffusion approximations. Finally, the authors discuss the novel issue of evaluating the overload created by the CAC procedure itself on network nodes. The article is complemented by several numerical and simulation results which illustrate the discussion.