A context-based simulation tool for design and evaluation of network processors

Network processor, a kind of highly integrated programmable circuit, attempts to strike a balance between performance and flexibility in network processing. Research on architecture design and system implementation concerning network processors requires powerful simulation tools. Many existing methods use execution-driven full-system simulators to build a virtual target platform running unmodified application binaries. However, they oversimplify the network environment in which the whole system is working. To address this issue, we develop a performance tool named Network Porcessor Network Simulator (NPNS) built upon a well-known network simulator—ns-2. This tool combines those full-system simulators to provide a unified framework for processor and software design within a network context. This article presents the principle, architecture and implementation issues of NPNS. To demonstrate the validity of the tool, two examples using the NPNS prototype to simulate the Intel IXP1200 network processor are illustrated and their performance is further evaluated. The performance results reveal the importance of considering network context for improving the accuracy of network models and achieving more realistic network simulations.