A low-cost strategy to provide full QoS support in Advanced Switching networks

Advanced Switching (AS) is an open-standard fabric-interconnect technology that is built over the same physical and link layers as PCI Express technology. Moreover, it includes an optimized transaction layer to enable essential communication capabilities, including protocol encapsulation, peer-to-peer communications, mechanisms to provide quality of service (QoS), enhanced fail-over, high availability, multicast communications, and congestion and system management.In this paper, we propose a strategy to use the AS resources that provides a good performance and QoS support at a low cost. When the system is considered as a whole rather than each element being taken separately, it is possible to use only two virtual channels (VCs) at the switches to provide a service like that with many more VCs. As a result, we obtain a noticeable reduction of silicon area and arbitration time. Our proposal is fully compatible with the AS specification and permits us to provide an adequate performance both for typical multimedia applications and for best-effort traffic.