A Simplified Communication Protocol on Dawning 2000

Point to point latency and bandwidth are two important factors to evaluate a cluster communication system. SCP is a Simplified Communication Protocol on Dawning 2000 which is a low level communication system based on PowerPC/AIX. The latency of SCP is limited to 9.6 /spl mu/s, and the peak bandwidth is reached when message length is 4 K. The paper mainly discusses the key points about the design and implementation of SCP. The paper gives the idea of improving the performance of a low level communication system by using a simplifying communication protocol, using zero memory copy, providing an efficient communication data path and balancing the work on host and NIC. Multiple services are provided to optimize the upper layers.