用于WDM光突发交换网的改进JIT信令协议

提出了一种用WDM光突发交换网的良好时间通信协议(MJIT-SP)该协议结合了光线路交换和光分组交换的优点与用于光突发交换的其他信令协议相似,MJIT-SP的特点也是采用带外控制信号处理来排除核心节点处对光缓存器的需求然而,与其它协议如JIT-SP相比,它能最小化数据源端的建立时间和最大化交叉连接的带宽利用率而且,MJIT-SP还能支持光网络中无连接和面向连接的数据包传递并介绍了MJIT-SP的基本结构并从三个方面分析了它的基本性能,即建立时间、端到端延时和信道占用时间然后,对本协议与JIT-SP的性能进行了比较,结果显示:MJIT-SP不仅优于JIT-SP,而且还克服了JIT-SP的一个缺点,即过长的信道占用时间此外,还给出了MJIT-SP的信令信息,尤其是非常关键的信号与脉座电平差(SETUP)消息MJIT-SP中的SETUP与JIT-SP中的SETUP不同,它需要给出数据包路由和交换所需的信息,包括数据包长度、比特率、SETUP与数据包之间的偏置时间以及数据业务的质量控制系统(QoS)要求等最后讨论了MJIT-SP两种可能的变化并且分析了它们的优缺点.

MODIFIED JUST-IN-TIME SIGNALING PROTOCOL FOR WDM OPTICAL BURST SWITCHING NETWORKS

It proposes a modified just in time signaling protocol(MJIT SP) for WDM optical burst switching (OBS) networks.This signaling protocol is designed for ultra low latency unidirectional transport of data bursts across an optical network.It combines the desirable features of optical circuit switching(e.g.wavelength switching,time division switching and space division switching)and optical packet switching.Like other signaling protocols for OBS,it also features out of band control signal processing that eliminates optical buffering of data burst at core nodes.Moreover,it can support both connectionless and connection oriented data burst forwarding in optical networks.It minimizes the source setup time,and maximizes the cross connect bandwidth efficiency,comparing other signaling protocols such as just in time signal protocol(JIT SP).In this paper, the architecture of the MJIT SP is motivated and described,and its basic performance is analyzed from threekey performance issues:setup time,end to end latency and channel hold time.Then,performance of MJIT SP is compared with that of JIT SP.The results show that the MJIT SP not only has the advantages of JIT SP,but also overcomes its one shortcoming long channel hold time.In addition,the signaling messages for the MJIT SP are presented also,specially the SETUP message that is very crucial to a successful data brust forwarding.The SETUP message differs from that of JIT because of giving necessary information about data burst for switching and routing.The information includes length of data burst,bit rate,delay duration between SETUP message and data burst,QoS requirement of traffic and offset of payload in data burst.All this parameters must be carefully designed when apply this protocol into practice.Finally,two possible variations of the MJIT SP are discussed,and their advantages and disadvantages are analyzed.