并行离散事件网络仿真系统的研究与实现

互联网的不可控、易变和不可预测的特性给网络协议的开发、调试和性能测试带来极大的困难.网络仿真系统构造可控、可重现网络状况的虚拟网络环境,可以在新协议新算法部署之前预测其可用性和性能.文中所述的并行离散事件网络仿真系统具有以下特点:(1)基于并行计算模型BSP的实时事件调度引擎-BREEN;(2)网络应用透明的灵活的交互机制;(3)重用基于流行仿真工具开发的网络模型.最后以网络路径瓶颈带宽测量和分布协作web缓冲系统作为应用实例,分别进行可用性评估和性能预测.

Research and Implementation of a Parallel Discrete Event Network Emulator

Intemet is characterized as a uncontrollable, variable and unpredictable infrastructure, this brings the difficulty of developing, debugging and evaluating network applications. Network emulation system constructs a virtual network environment which has the characteristics of controllable and repeatable network conditions. This makes it possible to predict the correctness and performance of proposed new technology before deploying to Intemet. In this paper we present a methodology for predicting the correctness and performance of applications based on the PARNEM, a parallel discrete event network emulator. PARNEM employs a BSP based real-time event scheduling engine, provides flexible interactive mechanism and facilitates legacy network models reuse. PARNEM allows detailed and accurate study of application behavior. Comprehensive case studies covering bottleneck bandwidth measurement and distributed cooperative web caching system demonstrate that network emulation technology opens a wide range of new opportunities for examining the behavior of applications.