可生存性虚拟网络映射模型及算法研究

发布时间：2018-07-17 02:38

【摘要】：随着网络用户数量的爆炸式增长,传统网络受到较大冲击,僵化问题越来越严重。近年来,网络虚拟化(Network Virtualization,NV)技术作为一种解决网络僵化问题的有效途径,受到了极大的关注。在NV问题的探究中,作为其中的一个重要研究内容—虚拟网络映射,即使众多的虚拟网络请求(Virtual Network Request,VNR)能够映射到同一个底层物理网络(Substrate Network,SN)上,以便使SN上的资源得以共享。但由于物理网络数量的有限性,网络通讯数量的增长受到了严重阻碍。鉴于此,本文提出了一种网络虚拟化(Network Virtualization,NV)技术,从而在较大程度上改善了网络僵化的程度。在当前,网络虚拟化技术评价的指标有多种,如SN对VNR的接受率,网速响应时间以及网络稳定性等。值得关注的是,随着网络用户数量规模的日益庞大,网络故障问题成为影响网络稳定性的重要因素。因此,如何提高网络的可生存性问题成为近年来研究的重要课题。现有的可生存性算法多集中于单方面提高网络的稳定性,这使得资源浪费问题日益突出,同时也出现了负载不均衡以及网络环境应用受限等问题。本文针对以上问题对网络生存性问题展开实验并探究,主要内容有以下几点:1)为满足不同用户的链路保护需求,提出一种可调整资源比例的可生存性虚拟网络映射算法GSVNE。GSVNE首先将物理网络链路资源动态预分为主要流和备份流资源两部分,前者是网络正常情况下,提供给用户的资源,后者是网络出现故障时,分配给用户的备用资源;然后,利用新型智能优化算法群搜索优化算法(Group Search Optimizer,GSO)进行优化求解;最后采用模拟仿真实验对算法性能进行验证。实验证明,该算法可以较好地满足用户的链路保护需求并提高资源利用率。2)由于网络用户数量的增多以及备用资源的设置,在资源相对较少的环境下易导致接受率不高,因此本文进一步提出了一种支持路径切割和资源共享的可生存性算法(GSBK E-Pc-Yshare),此算法支持虚拟请求的不同链路共享同一条物理链路来减少备用资源的使用量,即允许两条物理路径同时为虚拟链路提供备用资源,同时设备间的映射路径不再限制为单条,从而较大程度上提高网络的接受率。3)现实中多区域网络提供商环境是最常见的,但目前大多数的研究局限于单区域网络提供商环境。而现实生活中特别是对于数据安全性要求较高的网络用户,普通的单区域网络映射已很难满足需求。因此,本文提出一种支持跨区域映射的可生存性虚拟网络映射算法(Int D-GRC-SVNE),该算法支持跨区域映射,通过将通信用户映射到不同的区域网络以达到提高数据安全性的目的。同时,算法中引用了现有的新型度量GRC(衡量节点的潜在映射能力),使得物理网络的负载更加均衡,大幅度提高了网络接受率,获得了较高收益。
[Abstract]:With the explosive growth of the number of network users, the traditional network has been greatly impacted, and the problem of ossification is becoming more and more serious. In recent years, network virtualization (NV) technology, as an effective way to solve the problem of network fossilization, has received great attention. In the exploration of NV problem, as one of the important research contents, virtual network mapping, even though many virtual network requests (VNR) can be mapped to the same underlying physical network (SN), so that the resources on SN can be shared. However, due to the limited number of physical networks, the growth of network communications is seriously hindered. In view of this, this paper proposes a network virtualization NV (Network Virtualization NV) technology, which improves the degree of network fossilization to a large extent. At present, the network virtualization technology evaluation has a variety of indicators, such as SN acceptance of VNR, network speed response time and network stability. It is worth paying attention to, with the increasing number of network users, network failure has become an important factor affecting network stability. Therefore, how to improve the survivability of networks has become an important research topic in recent years. Most of the existing survivability algorithms focus on improving the stability of the network unilaterally, which makes the problem of resource waste become more and more prominent. At the same time, there are also some problems such as load imbalance and limited application in the network environment. Aiming at the above problems, this paper conducts experiments and probes into the network survivability problem. The main contents are as follows: 1) to meet the link protection needs of different users. A survivability virtual network mapping algorithm, GSVNE.GSVNE, which can adjust resource ratio, is proposed. Firstly, the physical network link resource is divided into two parts: the main stream and the backup stream resource. The former is the resource provided to the user under the normal condition of the network. The latter is the backup resource allocated to the user in the event of network failure. Then, a new intelligent optimization algorithm, Group search Optimizer GSO, is used to solve the problem. Finally, simulation experiments are used to verify the performance of the algorithm. Experimental results show that the proposed algorithm can meet the link protection needs of users and improve the resource utilization. 2) because of the increase in the number of network users and the setting up of backup resources, it is easy to lead to a low acceptance rate in a relatively small resource environment. Therefore, this paper further proposes a survivability algorithm (GSBK E-Pc-Yshare) that supports path cutting and resource sharing. This algorithm enables different links of virtual requests to share the same physical link to reduce the use of backup resources. That is, allowing two physical paths to provide backup resources for virtual links at the same time, mapping paths between devices are no longer restricted to a single path, thus greatly increasing the acceptance rate of the network. 3) in reality, multi-area network provider environments are the most common. However, most of the current research is confined to the single-area network provider environment. However, in real life, especially for network users with high data security requirements, it is difficult to meet the requirements of common single-area network mapping. Therefore, this paper proposes a survivability virtual network mapping algorithm (Int D-GRC-SVNE), which supports cross-region mapping and improves data security by mapping communication users to different area networks. At the same time, the existing new metric GRC (potential mapping ability of measuring nodes) is cited in the algorithm, which makes the load of the physical network more balanced, greatly improves the network acceptance rate, and gains higher income.
【学位授予单位】：山东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP393.01

【相似文献】