几种网络拓扑搜索方法的分析研究

文中旨在帮助人们在不同的网络拓扑要求和网络条件下选取合适的网络拓扑搜索方法。通过对网络层次、实用范围、拓扑粒度等方面进行分析比较，发现每种方法都不能对网络中所有设备完整准确地搜索，均各有其适用的范围、优点和局限性。若不能发现详细准确的网络信息，仅对网络的增长感兴趣，可选用基于DNS协议路由表的拓扑搜索；而用于发现网络中的主干拓扑，反映网络的整体状况，可选用基于SNMP协议网络拓扑搜索；对网络设备均支持OSPF协议且能动态地检测和报告网络拓扑的局部变化，可选用基于OSPF协议的网络拓扑搜索。所以在实际应用中应根据需要将多种技术有选择地结合来共同完成。     

一种校园网络的优化方案及应用

兰州石化职业技术学院是首批国家24所示范性高职院校之一,这些年随着校园信息化的不断开展,校园网内各种设备及接入网点也在不断增加,校园网内各种问题也日趋凸显,校园网安全面临严重威胁。本文针对校园网现状,提出一种基于交换机配置的校园网优化方案,并寄予具体的实施,为各高校校园网的优化提供一些参考与帮助。     

一种支持QoS的OSPF扩展算法

提出了一种扩展OSPF路由协议以支持QoS路由的算法. 根据主机的资源预留请求, 在OSPF域中动态地建立一条保证需求带宽的QoS通路. 并讨论了算法的可行性及适用范围.     

城域网路由设计

该文以宝安信息网为例,根据层次性路由、路由冗余、路由对称性、负载平衡、路由稳定性等设计要素,对城域网路由设计的要点进行了论述。     

Dynamic link sleeping reconfigurations for green traffic engineering

The high volume of energy consumption has become a great concern to the Internet community because of high energy waste on redundant network devices. One promising scheme for energy savings is to reconfigure network elements to sleep mode when traffic demand is low. However, due to the nature of today's traditional IP routing protocols, network reconfiguration is generally deemed to be harmful because of routing table reconvergence. To make these sleeping network elements, such as links, robust to traffic disruption, we propose a novel online scheme called designate to sleep algorithm that aims to remove network links without causing traffic disruption during energy‐saving periods. Considering the nature of diurnal traffic, there could be traffic surge in the network because of reduced network capacity. We therefore propose a complementary scheme called dynamic wake‐up algorithm that intelligently wakes up minimum number of sleeping links needed to control such dynamicity. This is contrary to the normal paradigm of either reverting to full topology and sacrificing energy savings or employing on‐the‐fly link weight manipulation. Using the real topologies of GEANT and Abilene networks respectively, we show that the proposed schemes can save a substantial amount of energy without affecting network performance.     

A Geographic Multi-Topology Routing approach and its benefits during large-scale geographically correlated failures

Large-scale geographical events can significantly disrupt network services. In particular, the routing churn that occurs during such large-scale events has been shown to cause significant impact in route stability and transient behavior. We take a Geographic Multi-Topology Routing (gMTR) approach for pre-planning of geographically correlated failures. Thus, in the event of a failure, the gMTR approach switches to a virtual topology that reduces the impact of routing changes that can result in dropped connections until new paths can be established. Two algorithms are proposed to generate virtual topologies, Geographic Coverage MTR (gcMTR) and Geographic Targeted MTR (gtMTR). The first method, gcMTR, is to create virtual topologies taking a network wide coverage approach for which we consider taking both a circular coverage approach and a hexagonal coverage approach. gtMTR, on the other hand, is a targeted approach that can be used in anticipation of a specific event where the knowledge of the impending event is available. We propose another algorithm that specifies a way to detect a geographic event and select a topology to use. We evaluated our approach on two network topologies and observed that the number of connections that are dropped during a geographic event can be reduced significantly using our gMTR approach, thereby reducing the impact to the non-affected part of the network. We performed an analysis of the topology size versus the disaster size, topology location versus disaster location, and general density of the topology. Finally, a simulation model of the larger topology is used to study the effects of geographically correlated failures both with gcMTR and using default topologies. This provides a way to assess the gains from using gMTR to mitigate the impact of large scale geographic impacts.     

DCC开销交叉技术在光传输网络中的应用

提出了一种利用DCC开销交叉技术建立DCC的解决方案,介绍了该方案的技术原理和实现途径,最后对该技术进行了测试验证,试验结果表明该技术方案是正确可行的。     

OSPF路由协议运行机制及算法的研究

为了研究OSPF运行机制和验证SPF算法,分析了OSPF的动态路由技术并利用实验加以验证,结果表明,OSPF不仅是一种最短路径优先算法,也是一种收敛速度快的动态路由协议,适合于多种网络拓扑结构。     

基于Packet Tracer的OSPF路由协议在IPv4和IPv6环境的仿真分析

本文基于Packet Tracer仿真软件,在对IPv4,IPv6与OSPF报文分析的基础上,通过设计多路由器的网络拓扑结构,完成对OSPF动态路由协议在IPv4和IPv6的环境下仿真分析,得出OSPF在2种IP协议下的区别,总结出OSPF动态路由协议在2种不同的特点,并对协议数据结构分析说明。     

不同物理网络结构的OSPF配置

OSPF是目前应用最广泛的动态路由协议,本文在对OSPF工作原理及特性进行剖析的基础上,对OSPF的几种典型使用方式进行了介绍。