On-chip communication architecture for OC-768 network processors

The need for network processors capable of forwarding IP packets at OC-192 and higher data rates has been well established. At the same time, there is a growing need for complex tasks, like packet classification and differentiated services, to be performed by network processors. At OC-768 data rate, a network processor has 9 nanoseconds to process a minimum-size IP packet. Such ultra high-speed processing, involving complex memory-intensive tasks, can only be achieved by multi-CPU distributed memory systems, using very high performance on-chip communication architectures. In this paper, we propose a novel communication network architecture for 8-CPU distributed-memory systems that has the potential to deliver the throughput required in next generation routers. We then show that our communication architecture can easily scale to accommodate a much greater number of network nodes. Our network architecture yields higher performance than the traditional bus and crossbar yet has low implementation cost. It is quite flexible and can be implemented in either packet or circuit switched mode. We compare and contrast our proposed architecture with busses and crossbars using metrics such as throughput and physical layout cost.