基于流量工程的ECRP设计与实现

对基于MPLS的流量工程进行了深入探讨与分析,并着重研究其关键技术:约束路由算法。主要包括以下几个方面:介绍MPLS技术的基本原理,并在此基础上分析了如何基于MPLS技术实现流量工程(MPLS TE);分析了当前的约束路由算法,提出了一种能用于某ATM交换机的增强型约束路由协议(Enhanced Constraint-based Routing Protocol,简称ECRP),它能够维护全网的拓扑及链路状态信息。从中选择满足用户约束条件的路由,使得整个网络在一定程度上达到流量均衡。     

基于NS2的MPLS流量工程仿真研究

MPLS被认为是下一代Internet骨干网络的核心技术,利用MPLS可以有效实施流量工程。文中对MPLS技术进行了介绍,针对流量工程的要求,给出了满足MPLS流量工程要求的系统模型。通过对仿真工具NS2的扩展,建立了一个MPLS流量工程仿真器,可以实现对MPLS转发技术和约束路由算法进行性能评估。仿真器的核心思想是,在标记交换路由器LSR模型中实现了标记分发、信令协议和路由协议扩展等基本功能;在标记边缘路由器LER模型上实现了对显示路由算法的支持。     

基于NS2的MPLS流量工程仿真研究

MPLS被认为是下-代Internet骨干网络的核心技术,利用MPLS可以有效实施流量工程.文中对MPLS技术进行了介绍,针对流量工程的要求,给出了满足MPLS流量工程要求的系统模型.通过对仿真工具NS2的扩展,建立了一个MPLS流量工程仿真器,可以实现对MPLS转发技术和约束路由算法进行性能评估.仿真器的核心思想是,在标记交换路由器LSR模型中实现了标记分发、信令协议和路由协议扩展等基本功能;在标记边缘路由器LER模型上实现了对显示路由算法的支持.     

MPLS流量工程路由优化机制的研究

对最小干涉算法进行了链路权值优化研究,提出集中和分布相结合的方式计算显式路由的方法.使用专门的策略和权值服务器PAWS为链路计算权值,标记边缘路由器LER实施分布式最小干涉算法,计算满足带宽的显式路由.通过路由算法及其体系结构的优化,提高了MPLS显式路由计算的效率和准确性,增强了MPLS流量工程系统的可扩展性.     

支持MPLS流量工程的LER体系结构设计

文中设计了支持MPLS流量工程的标记边缘路由器LER(LabelEdgeRouter)体系结构,对显式路由计算、MPLS信令协议以及包转发机制等进行了详细讨论。LER流量工程组件通过对现有路由器结构的改造,利用合适的显式路由ER(ExplicitRoute)算法,可以在ISP骨干网上提供负载均衡,实施MPLS流量工程。     

支持自愈恢复的MPLS路由算法

对当前支持流量工程的路由算法进行了分析和比较,详尽地论述了MPLS自愈恢复机制,通过对最小干涉路由算法进行改进,设计了一种支持自愈恢复的MPLS路由算法,使得它能有效利用网络资源的同时支持故障恢复。     

基于MPLS流量工程的约束路由的研究

约束路由的使用促进了基于MPLS的流量工程的发展和实现.简单介绍了MPLS流量工程中约束路由的技术框架,提出了在支持Diff-Serv的MPLSTE环境下实施约束路由的一种算法,使得在保证使用有效链路的同时也保证了链路的QoS.     

基于MPLS的IP语音网络恢复性能仿真分析*

提出了一种基于MPLS 的IP语音网络恢复性能评估方案,该方案利用OPNET Modeler工具构建一个基于MPLS的IP语音网络仿真平台,分析与评估基于MPLS的两种故障恢复技术。仿真结果表明,采用基于MPLS OAM技术的快速重路由算法可以有效地缩短流量重路由时间与改进IP语音网络服务质量,验证了基于MPLS OAM技术的FRR算法在VoIP网络系统中实现QoS性能网络优化的可行性。     

基于MPLS流量工程的重路由算法研究

概述了MPLS的流量工程和故障恢复机制。在区分服务网络环境中,描述了一种基于集中模型的多故障的重路由算法。采用以优先级属性划分LSP的策略,将带宽作为主要需求参数,满足了不同LSP的QoS要求。其实现是基于MPLS流量工程的约束路由的最优化方程。模拟示例分析验证了算法的可行性和优越性。     

基于双种群遗传算法的MPLS流量工程研究

针对因特网流量的快速增加和对服务质量要求的不断提高,为避免网络数据流过大造成拥塞问题,利用MPLS流量工程的路由算法成为业界研究的重点。介绍了MPLS流量工程的工作机制,并提出了数学模型。MPLS流量工程的关键问题是LSP的分布优化问题,针对这一问题的Np-hard特性,提出一种基于双种群策略的遗传算法求解方法,算法采用自然数编码来提高搜索效率。算法中,两个子种群周期性地交流最优染色体,进一步提高了性能。仿真实验表明,提出的算法能有效提高搜索速度,增加获得最优解的概率。     

无线传感器网络方向性分区路由算法

针对中小规模无线传感器网络路由算法效率不高的问题，提出了一种新的路由算法——方向性分区路由算法。新算法采用方向性信息传输及区域划分方法，便于信息融合及移动节点处理，路由维护简单，节能性好并易于实现。通过仿真实验与洪泛法及理想路由情况比较，结果表明该算法在数据包接收速率和节能性方面具有明显的优势。     

A necessary and sufficient condition for deadlock-free routing incut-through and store-and-forward networks

This paper develops the theoretical background for the design of deadlock-free adaptive routing algorithms for virtual cut-through and store-and-forward switching. This theory is valid for networks using either central buffers or edge buffers. Some basic definitions and three theorems are proposed, developing conditions to verify that an adaptive algorithm is deadlock-free, even when there are cyclic dependencies between routing resources. Moreover, we propose a necessary and sufficient condition for deadlock-free routing. Also, a design methodology is proposed. It supplies fully adaptive, minimal and non-minimal routing algorithms, guaranteeing that they are deadlock-free. The theory proposed in this paper extends the necessary and sufficient condition for wormhole switching previously proposed by us. The resulting routing algorithms are more flexible than the ones for wormhole switching. Also, the design methodology is much easier to apply because it automatically supplies deadlock-free routing algorithms     

基于Omnet++的WSN路由实验教学平台

在无线传感器网络(WSN)教学过程中开展实验较为困难。为此,提出一种基于源代码级合成的WSN路由实验教学平台。采用模块化的方法将路由算法的通用部分固化,通过用户输入路由参数配置不同的路由算法,允许学生在进行路由实验时只关注于路由协议的关键算法,且可自行设计一些路由算法进行仿真测试。评测结果表明,大部分使用者都能在2个课时内成功完成一个以上的路由算法,简化仿真实验的难度与工作量。     

A necessary and sufficient condition for deadlock-free adaptiverouting in wormhole networks

Deadlock avoidance is a key issue in wormhole networks. A first approach by W.J. Dally and C.L. Seitz (1987) consists of removing the cyclic dependencies between channels. Many deterministic and adaptive routing algorithms have been proposed based on that approach. Although the absence of cyclic dependencies is a necessary and sufficient condition for deadlock-free deterministic routing, it is only a sufficient condition for deadlock-free adaptive routing. A more powerful approach by J. Duato (1991) only requires the absence of cyclic dependencies on a connected channel subset. The remaining channels can be used in almost any way. In this paper, we show that the previously mentioned approach is also a sufficient condition. Moreover, we propose a necessary and sufficient condition for deadlock-free adaptive routing. This condition is the key for the design of fully adaptive routing algorithms with minimum restrictions, An example shows the application of the new theory     

QoS动态路由算法分析

保证服务质量(QoS）的通信是当今网络发展的必然趋势之一。动态路由算法可根据网络拓扑和负载情况实时为业务选择路径。其合理性和有效性对于网络资源的优化使用及网络运行性能起着重要作用。文章阐述了QoS动态路由算法的研究内容：链路量度的选择、选路原则、改进Bellman-Ford算法和Dijkstra算法以及算法的触发,并总结了QoS路由算法目前存在的几个问题。     

基于图卷积神经网络的智能路由算法

使用特定数学模型的路由转发算法难以满足用户多样化的服务质量需求,基于深度学习的智能路由方案因具有准确性、高效性、通用性等优势,成为路由决策的发展方向。然而,目前多数智能路由算法在网络拓扑动态变化时需要重新训练,造成路由更新不及时,难以应对网络拓扑动态变化。提出一种基于图卷积神经网络（GCN）的智能路由算法。线下利用提前采集的网络信息,根据路由开销标签训练GCN智能路由模型,通过该模型输出单跳路由开销。线上采集实时信息并根据模型输出的路由开销结果对网络层路由协议进行调整,计算最小路由开销的路由路径,实现自适应网络更新。算法利用GCN的图数据结构处理不规则的网络拓扑,通过图卷积算子自动提取特征解决路由网络多属性参数提取的问题,同时引入模糊C均值算法进行网络状态离散化分析,为数据集生成标签,从而有效监督GCN模型训练。实验结果表明,该算法较ECMP、DRL-TE和SmartRoute算法路由性能更好,其平均丢包率、时延和吞吐量指标均为最优,且相较于单一的流量模式具有更强的泛化能力。     

具有路由性能和蚁群优化的移动P2P路由策略*

目前的移动P2P网络路由策略不能较好适应网络拓扑结构的动态多变、网络和移动设备的资源有限等特点,以及不能较好解决路由建立和维护所带来的网络拥塞和资源消耗。针对上述问题,采用有限洪泛路由查询和移动agent路由查询相结合的策略,为每个移动节点提供丰富可靠、及时高效的路由信息。同时,使用改进的蚁群算法,综合考虑网络带宽、时延等多个路由性能指标,作为路由策略中路由选择机制。仿真研究证明,将所提出的理论与方法应用于移动P2P的路由选择和维护等问题,本算法在控制消息的开销、平均响应效率等方面具有良好的性能,对于网络     

Parametric Evaluation of Routing Algorithms in Network on Chip Architecture

Considering that routing algorithms for the Network on Chip (NoC) architecture is one of the key issues that determine its ultimate performance, several things have to be considered for developing new routing algorithms. This includes examining the strengths, capabilities, and weaknesses of the commonly proposed algorithms as a starting point for developing new ones.
Because most of the algorithms presented are based on the well-known algorithms that are studied and evaluated in this research. Finally, according to the results produced under different conditions, better decisions can be made when using the aforementioned algorithms as well as when presenting new routing algorithms. In this research, we first describe the existing algorithms include: XY, YX, Odd- Even and DyAD. We then evaluate each of the routing algorithms which naturally have their own strengths and weaknesses under different conditions. In the first scenario, based on the criteria of average latency, average throughput and average energy consumption in determining the final performance of the network on the chip, we show the algorithms in terms of their performance by deterministic and adaptive routing algorithms. In the second scenario, we evaluate the algorithms based on the network size and the number of cores on the chip. As a result, these algorithms can make better decisions when using these algorithms as well as when presenting new routing algorithms, considering the results produced under different condition.     

QoS based multicast routing algorithms for real time applications

In recent years, there has been a lot of interest in providing real-time multimedia services like digital audio and video over packet-switched networks such as Internet and ATM. These services require certain quality of service (QoS) from the network. The routing algorithm should take QoS factor for an application into account while selecting the most suitable route for the application. In this paper, we introduce a new routing metric and use it with two different heuristics to compute the multicast tree for guaranteed QoS applications that need firm end-to-end delay bound. We then compare the performance of our algorithms with the other proposed QoS-based routing algorithms. Simulations were run over a number of random networks to measure the performance of different algorithms. We studied routing algorithms along with resource reservation and admission control to measure the call throughput over a number of random networks. Simulation results show that our algorithms give a much better performance in terms of call throughput over other proposed schemes.     

SDN中绿色路由的信令开销控制

为了降低在绿色路由条件下SDN控制器的信令开销,本文在SDN单控制器域中研究能量效率和信令开销之间的权衡。首先构建一个整型线性规划,在考虑整个网络能量消耗的基础上建立最小化控制器开销的目标函数;其次设计两种启发式算法来寻求该问题的近似最优解。仿真结果表明,在活跃链路数相同条件下,两种算法的控制器信令开销更小,故本文设计的启发式方法在绿色路由条件下可以减少控制器处理初始请求的信令开销。