基于预留带宽的光纤通道交换网硬实时通信

Hard real-time communication in fibre channel based on bandwidth reservation

为了保证光纤通道(FC)交换网中硬实时通信,提出一种采用通用处理器共享(generalized processor sharing)调度方式交换机构建交换网,并且采用模拟退化算法根据数据流硬实时通信需求找出交换网ISL(inter-switch link)权重参数和数据流预留带宽参数优化配置的方法.在对FC网络以及GPS调度方式进行分析的基础上,建立基于光纤通道交换网的硬实时通信模型,将保证硬实时通信问题转换为组合优化问题;构造了最小预留带宽和目标函数,并采用模拟退火算法找出该问题的最优解.仿真实验结果验证了该方法的有效性,但是通过可接受解和最优解的实验结果比较发现最优解并不能总是获得最佳的系统延迟时间率.

To guarantee hard real-time communication in fibre channel fabric, generalized processor sharing （GPS） scheduling switches were used to build fibre channel （FC） fabric, and simulated annealing algorithm was used to find the fabric＇s link weight and GPS bandwidth reservation configuration parameters according to data streams＇ real-time requirements. After analyzing FC fabric and GPS scheduling, a FC fabric model for hard real-time communication was built, and the hard real-time problem was turned into a combinatorial optimization problem. Then a minimum bandwidth reservation sum objective function was designed, and simulated annealing algorithm was used to find the best solution. The framework was verified by simulation with random topology and data streams with random hard real-time requirements, and all data streams＇ worst-case delays met targets. Simulation results comparison between acceptable solutions and best solutions show that the fabric configured with best solution cannot always get the best sys- tem delay rates.