基于部分冗余合并的OBS网络冲突解决机制

为了降低光突发交换网络中突发包的丢失率、减小网络延时、提高网络信道的利用率,采用了一种新型考虑优先级的基于冗余合并的突发包冲突解决机制。算法增加了回退信道作为保护信道,根据业务的优先级对冲突的突发包进行分段,使无法顺利传送的突发包碎片进入到回退信道;同时,考虑到网络中存在着很多短小而难以利用的信道资源,算法将回退信道里的突发包碎片进行多次克隆,多个克隆碎片和由上游节点到来的突发包合并成粒度可变的虚拟突发包发送,克隆碎片的优先级定义为最低,以保证不抢占正常突发包的信道资源。结果表明,相比以往的冲突解决算法,此算法具有较低的丢包率、相对小的延时率和优越的信道利用率。

A contention resolution based on segment redundant recombination in OBS networks

To decrease the byte loss probability of data burst, reduce the time delay cost and grantee the high usage efficiency of channel resource, a novel contention resolution was proposed based on segment redundant recombination in optical burst switching( OBS) networks. In this scheme, a special channel type called back-off channel was classified. When two bursts contents, the lower priority one will be separated and the segments will be sent back to upstream node by back-off channels. To grantee high efficient usage of channel resources, the segments will be cloned as many copies to fill the void of data channels. These copies will be recombined with the original data burst as virtual burst which can be separated flexibly. Moreover, the priority of the burst on back-off contention was set to the lowest to balance out the cost of segmentation copies. The simulation results show that, this contention resolution method reduces packet loss rate and time delay in OBS networks effectively, and use the channel resources efficiently.