开放最短路径优先协议相关问题研究
文献类型：学位论文
| 作者 | 王玲芳 |
| 学位类别 | 博士 |
| 答辩日期 | 2004 |
| 授予单位 | 中国科学院声学研究所 |
| 授予地点 | 中国科学院声学研究所 |
| 关键词 | 路由查找 协议测试和开发 网络分析 左向网络 |
| 其他题名 | Studies on OSPF Related Issues |
| 中文摘要 | 论文的重点是探讨与开放最短路径优先协议有关的各种问题，本题目提出的直接缘由在于作者参与的《IPv6城域示范系统》项目，更长远的思考着眼于护v6协议不可阻挡的未来远景，以及路由技术在数据通信领域所扮演的越来越重要的角色。论文从四个方面对与OSPF相关的问题进行了深入思考，为了说明这些问题之间的关系，画出关联图如下：图中，灰色椭圆区是论文所围绕的核心，OSPF是自治域内的路由选择1办议，路由选择协议的口的是寻找源和口的地之间的最短路径，即构造路由表。那么路由器是如何使用路由表的，在使用过程中又会产生｝哪些问题？通过考察常规路由查找算法，产生了面向对象路由查找的思路。在考虑常规协议测试工具能够扩展解析OSPFv3协议数据时，进而思考能否开发通用的协议测试工具，十是便产生单状态、多状态协议产生器和分析器。由OSPFv3协议衍生出地址问题（IPv6 128位地址空间ID和IPv432位地址空间的问题），进一步深入思考IPv4地址的表示法，之后导出产生左向网络的概念和思路。OSPF深深植根于Dijkstra算法，这是图论问题中的经典算法，图论比较早应用于电路网络，而计算机网络也可以应用图论，两种应用是否有互相借鉴之处，就产生了电路网络和计算机网络之问的横向关联。对上面提到的四个问题，简述如下：（l）研究开放最短路径优先协议，就必然要研究路由查找算法，论文通过考察各种路由查找算法，提出面向对象路由查找算法，即分布式路由计算。论文提出基于路由转发的下一跳进行路由选择计算，即针对每一跳建立硬件路由计算装置，然后经过二次判决，从总体上降低核心路由器的硬件实现复杂度；（2）在协议开发和测试过程中，一般情况下，协议实现和测试人员要面对·各利，复杂协议的解析细节，而且对于每种协议，人们又不得不编制专门的测试工具，来测试协议的一致性和兼容性。为了解决这种窘境，本文提出一种根据用户定义的协议数据格式自动生成协议测试流程的思路和方法一一单状态和多状态协议数据产生器及分析器。（3）从网络使尹日特征、网络扭差来源特征和计费特征等三个方面综合考察电路网络和计算机网络的差别。受电路网络规律的启发，在这里给出两种算法：网络中的源和目的节点之间等价代价的计算力一法和网络链路带宽逐步分层法。对后一利1算法，给出形式化描述，并指出算法用途。据日前我们了解，本论文是首次将电路网络和计算机网络作相似性比较。而月给出的两种算法在其他文献中，也没有见到类似的陈述。（4）扩展IPv4地址空间的另一方法—左向网络，能够将IPv4地址空间扩大l倍，而且在原有IPv4的基础上，开发工作量非常少。这种扩展是对IPv6难于开发、配置和使用的反思，重新考察发掘IPv4自身的潜力。人们习惯于网络掩码从左到右，逐步延伸，而网络部分逐步扩大、主机部分逐步缩小的情况。在这里，论文提出网络掩码可以从右向左延伸，并进而考察了如此延伸所带来的各种问题，如路由转发和路由表的生成。为了将这种方式的网络与原有网络区别开来，按照网络掩码的延伸方向，将网络定义为左向网络和右向网络，并且在本部分还给出了左向网络和右向网络并存的可能性和现实性。由于论文内容较多，互相之间关联性不大，故将前两个问题作为正文内容，后两个问题的思路还处于萌芽状态，日前还不成熟，作为附录列于正文之后，供大家参考。另外，除了研究性工作之外，针对协议解析工具解析OSPFv3协议数据报文的困难，我们给出扩展Sniffer解析程序的原理、方法和具体实现。对OSPFv3协议开发和调试希望能够有所帮助。 |
| 英文摘要 | The emphasises of this paper are issues related to Open Shortest Path First Protocol(OSPF). The direct source comes from IPv6 Metropolitan Demonstration System which the author participated in. Irresistible and prosperous future of IPv6 also has its share in shaping these ideas, more and more important role which routing technology plays in data communication domain is another catalyst. The paper has delved into four issues related to OSPF. In order to illustrate relations-between OSPF and issues, here presents co-relations diagram. In diagram, gray part is the core of the paper. OSPF is routing protocol within autonomous domain, whose object is finding out the shortest path from source to destination, also puts as constructing routing table. Then how router manipulates this routing table, and during the processing procedure what kind of issues origin from it? Along this thinking path produces the idea of Object Oriented Routing Search. In addition to expand general protocol analyzer by decoding OSPF version 3 PDU(protocol Data Unit) data, we were wondering if there are more general protocol debug tools, the brain-storm result is that single and multiple state protocol data generator and analyzer. OSPF version 3 is for IPv6 stack, whose address length is 128 bits long instead of IPv4's 32 bits. By introspecting the presentation of IPv4's address space, we invent the concept of left motion network and resolutions without IPv6 's implementation obstacles. OSPF lays its base on dijkstra algorithm which is one typical algorithm in graph Studies of OSPF Related Issues theory. Graph theory applied in circuit network in comparatively early years (19 century), computer network also utilizes graph theory. Whether these two applications have some commutable similarities? By examining above-mentioned similarities, here forges the correlation between circuit network and computer network. Details these four issues as following: If one studies Open Shortest Path First protocol, he should know how routers utilize the protocol to generate routing tables, how routers operate routing tables as one packet incomes. The paper surveys sorts of routing table's searching algorithms, puts forward object oriented routing table searching algorithm, also called distributed routing computing. The paper describes routing computing based on forwarding entry-next hop, for every next hop builds hardware routing computing facilities, on their outputs make a selection, therefore decreasing hardware implementing complexity of core routers from a whole scale. During the process of protocol development and debugging, employees who implement and debug protocol usually confront with interpreting details of all sorts of complicated protocol. Moreover they have to code particular debugging tools for every specific protocol intending to test conformity and compatibility. To break this embarrassment, this paper presents an idea and method of generating protocol's debugging flow on the basis of protocol data unit defined by protocol designer-single state and multiply state protocol data generator and analyzer. From characteristics of network utilization, network voltage source and billing, this paper compares circuit network with computer network. Enlightened by circuit network laws, here gives two algorithms: computing equivalent cost between source and destination in network, and gradual layering of link's bandwidth. For the latter algorithm, the paper shows its formal description and points out in which network scenarioes should benefit from it. As far as we have known, there aren't other literatures which make similarity comparation between circuit network and computer network. Furthermore, the two algorithms have no tracks in other papers. Another technique expands IPv4 address space-left-motion network, it doubles the IPv4 available addresses, and if IPv4's experience and stack could be applied, the implementing labor may be small comparing to IPv6. The expansion is the result of deep thought of IPv6 difficulties in development, configuration as well as deployment; it digs out IPv4's potentiality in address space. People used to network mask (continuous Is) from left to right where the network part gradually is enlarged and host part dwarfed bit by bit. The paper argues that network mask may be enlarged from right to left, and looks inside several issues by doing so, such as packet forwarding and routing table generation. To distinguish this kind of network from usual network, the paper defines left-motion network and right-motion network according to the way network mask enlarged. Furthermore, the paper also analyzes coexistence possibility and realization of left and right networks. Due to the many more topics presented in this paper and loose coiTelations between each other, the first two issues mentioned above are laid as main content, the other two issues are put at the end of this paper as appendix mainly because they are immature and lack of practical implementation. In addition to research work, this paper gives one pi'actical work for compensation. To overcome the difficulty of OSPFv3 protocol data packet's interpretation in Sniffer, this paper describes Sniffer's OSPFv3 extensiton interpretation scheme, way and implementation. |
| 语种 | 中文 |
| 公开日期 | 2011-05-07 |
| 页码 | 129 |
| 源URL | [http://159.226.59.140/handle/311008/844]  |
| 专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
| 推荐引用方式 GB/T 7714 | 王玲芳. 开放最短路径优先协议相关问题研究[D]. 中国科学院声学研究所. 中国科学院声学研究所. 2004. |
入库方式： OAI收割
来源：声学研究所
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