基于弹性标签的多跳虚拟链路交换机制设计与实现

发布时间：2018-06-29 22:02

本文选题：网络虚拟化 + 虚拟链路　；参考：《国防科学技术大学》2014年硕士论文

【摘要】：网络虚拟化技术是通过在相同的物理网络基础设施上进行资源的切分,构建多个并存虚拟网络的基础支撑技术。不同的虚拟网络内运行的流量互不干扰,从而可以在不影响现有网络工作的情况下,用来实验新的网络体系结构;不同的虚拟网络,也可以运行异构的协议栈,为不同的应用提供不同的服务保障。因而,网络虚拟化技术是当前学术研究的热点,可以解决物理网络资源的利用率低下、新型的体系结构无法进行充分的实验、许多新增业务的不同需求难以同时满足等问题。但是由于虚拟网络的链路依托于物理网络链路,存在拓扑紧耦合问题,使得虚拟网络的拓扑无法独立于物理网络,按照用户的需求动态创建。本文为了克服上述问题,结合网络虚拟化技术和现有的交换机制,提出了基于多跳虚拟链路的快速交换机制。该机制在虚拟网络中使用标签交换的设计理念,在多跳虚拟链路入口结点处打上到多跳虚拟链路出口结点的“标记”,中间结点不处理网络层协议,进行多跳虚拟链路报文的快速交换。为提高虚拟网络可靠性,本文在结合现有故障修复方案的基础上,提出了基于弹性标签的多跳虚拟链路快速交换机制。本文的主要研究成果如下:1)提出了基于多跳虚拟链路的网络虚拟化模型。该模型基于构建多跳虚拟链路的需求,对现有网络虚拟化模型进行了改进,将现有的网络虚拟化模型的数据平面纵向切分为转发引擎数据平面和多跳虚拟链路数据平面,转发引擎平面共享多跳虚拟链路平面,实现虚拟网络接口报文,在多跳虚拟链路平面中的快速交换。2)提出了转发引擎数据平面和多跳虚拟链路数据平面间的虚拟接口映射机制。该机制可以灵活完成多跳虚拟链路数据平面的物理接口到转发引擎数据平面的虚拟接口的映射,在发送报文给转发引擎数据平面时,将物理接口映射为虚拟接口,在收到转发引擎数据平面的报文时,将虚拟接口映射为物理接口。3)提出了基于弹性标签的多跳虚拟链路抗毁机制。该机制主要为虚拟网络中的报文提供备份路径转发,在链路或者节点故障时,能够对报文进行本地处理或者回溯到上游节点进行处理,使数据报文具有“弹性”,提高了虚拟网络的可靠性。4)使用click开源软件,实现了基于弹性标签的多跳虚拟链路交换机制的原型系统,对多跳虚拟链路交换机制和基于弹性标签的多跳虚拟链路的转发性能进行了测试,通过对比实验结果,分析了转发性能的影响因素。
[Abstract]:Network virtualization technology is a basic supporting technology to construct multiple virtual networks by splitting resources on the same physical network infrastructure. The traffic running in different virtual networks does not interfere with each other, so that they can be used to experiment with new network architectures without affecting the work of existing networks, and different virtual networks can also run heterogeneous protocol stacks. Provide different services for different applications. Therefore, network virtualization technology is a hot topic in current academic research. It can solve the problems of low utilization of physical network resources, inadequate experiments of new architecture, and the difficulty of meeting the different requirements of many new services. But because the link of virtual network depends on the link of physical network, there exists the problem of topological tight coupling, which makes the topology of virtual network unable to be independent of physical network, which is created dynamically according to the user's demand. In order to overcome the above problems, a fast switching mechanism based on multi-hop virtual link is proposed by combining the network virtualization technology and the existing switching mechanism. In this scheme, label switching is used in the virtual network to mark the exit node of the multi-hop virtual link at the entrance node of the multi-hop virtual link, and the middle node does not deal with the network layer protocol. Fast exchange of multi-hop virtual link packets. In order to improve the reliability of virtual network, this paper proposes a fast switching mechanism of multi-hop virtual link based on elastic label based on the existing fault repair schemes. The main research results of this paper are as follows: 1) A network virtualization model based on multi-hop virtual link is proposed. Based on the requirement of constructing multi-hop virtual link, this model improves the existing network virtualization model and divides the data plane of the existing network virtualization model into forwarding engine data plane and multi-hop virtual link data plane vertically. The forwarding engine plane shares the multi-hop virtual link plane to realize the virtual network interface packets. The fast switching between the forwarding engine data plane and the multi-hop virtual link data plane is proposed. The virtual interface mapping mechanism between the forwarding engine data plane and the multi-hop virtual link data plane is proposed. This mechanism can flexibly map the physical interface of the multi-hop virtual link data plane to the virtual interface of the forwarding engine data plane, and map the physical interface to the virtual interface when sending packets to the forwarding engine data plane. When receiving the packets from the data plane of the forwarding engine, the virtual interface is mapped to the physical interface. 3) A resilient label based multi-hop virtual link survivability mechanism is proposed. This mechanism mainly provides backup path forwarding for packets in virtual network. In the event of link or node failure, the mechanism can process packets locally or back to upstream nodes, making data packets "flexible". Using click open source software, the prototype system of multi-hop virtual link switching mechanism based on elastic label is implemented. The multi-hop virtual link switching mechanism and the forwarding performance of multi-hop virtual link based on elastic label are tested. By comparing the experimental results, the factors affecting forwarding performance are analyzed.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.0

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