Scalable low-cost QoS support for single-chip switches

Virtual channels (VCs) are a popular solution for the provision of quality of service (QoS). Current interconnect standards propose 16 or even more VCs for this purpose. However, most commercial implementations do not offer so many VCs because it is too expensive in terms of silicon area. Therefore, a reduction of the number of VCs necessary to support QoS can be very helpful in the switch design and implementation. We have shown that this number of VCs can be reduced if the system is considered as a whole rather than each element being taken separately. Some of the scheduling decisions made at network interfaces can be easily reused at switches without significantly altering the global behavior. In this paper, our aim is to explore the scalability of the technique, considering the restrictions of the final chip implementation