一种基于图神经网络的SDN路由性能预测模型

软件定义网络作为未来网络架构的发展方向,通过分离数据平面与控制平面高效设定路由方案.而在路由方案的优化过程中,准确预估给定路由方案下的网络性能是其关键.本文基于图神经网络建模网络中物理链路与路由方案路径的关系,在给定的路由方案与网络流量下对网络中的各项端到端性能指标(如延迟、抖动)进行准确预估,以辅助优化路由方案.本文基于OMNeT++来生成数据并进行实验,实验结果表明本文提出的模型能够针对延迟抖动等端到端性能指标进行准确预估,预估平均相对误差不超过4.1％.实验也对比了传统最短路径路由算法与基于该预测模型给出的最优路由方案下的端到端性能,相比传统最短路径路由算法,平均延迟和平均抖动分别降低了19.8％和33.52％,最大延迟和最大抖动降低了36.18％和35.45％.     

结点有拥塞的动态最短路径问题的算法研究

最短路径问题在交通运输领域以及网络路由选择方向都有着重要的应用.本文在有必经结点且所经结点无序的最短路径算法的基础上,研究结点有拥塞且拥塞程度是动态变化的最短路径问题.对于这种情况的研究,在交通运输领域的高速公路以及局域网络上的路由选择都有着重要的应用.文中对结点的权值,即拥塞程度的预测采用了Kalman滤波方法,并用改进了的Dijkstra算法求解结点间的最短路径.相关实验结果及分析表明,该方案可以有效地解决结点有拥塞且拥塞动态变化的最短路径问题.     

分布式数据库系统动态数据邮递的QoS模型

在信息通讯中传统的单播网络传输,一般采用Dijkstra最短路径算法来建立点到点的最小路径计算。文章针对广域网分布式数据库系统动态、实时数据交换路由问题,对传统的单播网络传输的Dijkstra算法进行改进,提出了一种平衡网络负载的Qo S的路由算法。     

基于双层递归神经网络的路由优化算法

研究分组交换网的路由选择及流量分配问题,以网络的平均时延为优化目标函数。为使问题的解能实时、可靠地完成,将一种用于最短路径计算的双层递归神经网络应用于路由选择的流量导数法中。仿真结果表明,该算法在收敛的可靠性和计算的实时性方面有所提高。     

一种适合于移动Ad Hoc网络的路由协议WPRP

针对无线Ad Hoc网络特点,提出了一种无线路径发现路由协议(Wireless Path Finding Routing Protocol,WPRP)。对WPRP协议进行了简要概述,分别介绍了采用最短路径算法(Short Path Algorithm,SPA)查找最短路径;递归环路检测算法(Recursive Loop Check Algorithm,RLCA)消除路由环路;路由校验实现节点间路由同步;自适应时间调节机制进一步减少网络冲突、降低网络开销等方法以及实现过程。OPNET仿真结果表明,与OLSR协议相比,WPRP具有较小的路由开销和较快的收敛速度,是一种动态路由协议,适用于无线Ad Hoc网络。     

基于广义对数函数的统一路由策略

通过对最短路径路由策略、有效路由策略、最小信息路径路由策略的算法以及广义对数函数进行研究发现：将广义对数函数内的变量进行部分修改可实现以上三种算法的统一,并且通过对此种统一算法进行改进并且仿真发现,在此统一算法变量连续变化的同时,某些路由策略在复杂网络中的表现同样具有连续性。这表明此种算法可以将以上三种路由策略进行完美的统一。     

智能光网络的路由技术

本文比较了传统IP网络和智能光网络路由技术的差别,介绍了满足QoS需求的智能光网络路由技术和适应智能光网络需要的路径选择算法的基本概念,设计基础,着重描述了在基于GMPLS扩展条件下约束最短路径算法的设计思路.     

传感器网络中基于最短路径树的低延时节能路由算法

借助图论中最短路径和最小生成树的原理,在无线传感器网络中构建若干棵以Sink节点为根的最短路径源路由树。与最小生成树相比,最短路径树能保证路径上大部分节点找到节点间RSSI较强的通讯路径并以较少的跳数把数据传输给Sink节点,而最小生成树中的节点则需较多跳数。因此,提出的算法在一定程度上降低了延时。算法通过事先设定最低RSSI和节点最大剩余能量MRE来构建路由树,并修改已存在的路由算法,从而保证节点通讯的可靠性和网络的节能。     

基于带宽和跳数的流量工程动态路由选择算法研究

随着网络规模和网络硬件的快速发展,支持流量工程的路由器解决方案已经成为一种趋势,而流量工程动态路由选择算法则是流量工程方案的一个重要组成部分.本文分析了流量工程路由算法的研究现状,提出了以跳数和带宽作为量度的流量工程路由算法数学模型,并给出了路由算法规则.最后,通过计算机仿真验证了该算法的可行性和相对于只采用现行最短路径优先路由选择算法的优越性.     

基于BP神经网络和蚁群的WSN分簇算法的研究

在研究经典低能量自适应分簇路由算法的基础上,提出基于BP神经网络和蚁群的无线传感器网络分簇路由算法。在分簇阶段将BP神经网络应用于每个分簇结构中,把采集的大量信息通过设计好的神经网络模型融合得到反映原始数据特征的少量数据信息。在数据传递阶段将蚁群算法应用到簇间路由机制中,寻找簇头到基站的最佳路径。将融合后的数据通过优化的路径传送到汇聚节点。仿真结果表明,该算法和LEACH算法相比,有效地均衡了网络的能量消耗,并延长了网络的生命周期。     

跳频分组无线网的路由算法分析

跳频分组无线网抗干扰性好,保密性强,广泛应用于战术通信系统。讨论了几种跳频分组无线网的路由选择算法,着重分析了针对传输多类型分组跳频网的ALR路由算法,并将此路由算法的性能与DAR算法的性能进行了比较,证实了该算法在吞吐量、端-端正确传输率等方面都优于传统的方法。     

On the fundamental tradeoffs between routing table size and network diameter in peer-to-peer networks

We study a fundamental tradeoff issue in designing a distributed hash table (DHT) in peer-to-peer (P2P) networks: the size of the routing table versus the network diameter. Observing that existing DHT schemes have either 1) a routing table size and network diameter both of O(log/sub 2/n), or 2) a routing table of size d and network diameter of O(n/sup 1/d/), S. Ratnasamy et al. (2001) asked whether this represents the best asymptotic "state-efficiency" tradeoffs. We show that some straightforward routing algorithms achieve better asymptotic tradeoffs. However, such algorithms all cause severe congestion on certain network nodes, which is undesirable in a P2P network. We rigorously define the notion of "congestion" and conjecture that the above tradeoffs are asymptotically optimal for a congestion-free network. The answer to this conjecture is negative in the strict sense. However, it becomes positive if the routing algorithm is required to eliminate congestion in a "natural" way by being uniform. We also prove that the tradeoffs are asymptotically optimal for uniform algorithms. Furthermore, for uniform algorithms, we find that the routing table size of O(log/sub 2/n) is a magic threshold point that separates two different "state-efficiency" regions. Our third result is to study the exact (instead of asymptotic) optimal tradeoffs for uniform algorithms. We propose a new routing algorithm that reduces the routing table size and the network diameter of Chord both by 21.4% without introducing any other protocol overhead, based on a novel number-theory technique. Our final result is to present Ulysses, a congestion-free nonuniform algorithm that achieves a better asymptotic "state-efficiency" tradeoff than existing schemes in the probabilistic sense, even under dynamic node joins/leaves.     

Lifetime Maximization Based on Coverage and Connectivity in Wireless Sensor Networks

We consider information retrieval in a wireless sensor network deployed to monitor a spatially correlated random field. We address optimal sensor scheduling and information routing under the performance measure of network lifetime. Both single-hop and multi-hop transmissions from sensors to an access point are considered. For both cases, we formulate the problems as integer programming based on the theories of coverage and connectivity in sensor networks. We derive upper bounds for the network lifetime that provide performance benchmarks for suboptimal solutions. Suboptimal sensor scheduling and data routing algorithms are proposed to approach the lifetime upper bounds with reduced complexity. In the proposed algorithms, we consider the impact of both the network geometry and the energy consumption in communications and relaying on the network lifetime. Simulation examples are used to demonstrate the performance of the proposed algorithms as compared to the lifetime upper bounds.     

多域光网络中的动态RWA算法研究

随着光网络规模的不断增大,下一代智能光网络将被划分为多个路由域进行分布式管理.由于在这种具有分布式特点的多域光网络中,每个路由域只了解本地子网内的拓扑和资源信息,因此以往光网络中已有的基于全网信息的动态RWA算法将不在有效.文章首先分析了多域光网络中的动态RWA问题,然后针对多域网的特点对已有的RWA算法进行了修改,并在给定的多域光网络模型中对该算法进行了仿真研究.结果表明:在多域网络环境下,以往的动态RWA算法急需改进.     

一类基于源路由的多约束实时组播路由优化控制算法

随着Internet网络的不断发展,它将成为未来网络服务的平台,而未来网络服务的种类又是多种多样的,既有传统的尽量服务(Best-Effort Service)应用,又有对网络服务质量 [1](QoS:Quality of Service)有着特殊需求的应用.本文探讨了如何在网络层路由这一层面进行QoS组播路由支持的问题.目前,已有许多组播QoS路由算法提出,在QoS路由性能、网络资源使用效率以及路由吞吐率等方面取得了许多好的成果.针对这些QoS路由算法中存在的一些问题,提出了一种组播QoS路由算法.实验结果表明:该算法在适应网络拓扑结构、网络规模、对称/非对称链路负载等方面,与其它QoS路由算法相比,在算法性能上有了一定的改进.     

基于博弈论的无线传感器网络路由算法研究

在通过博弈论概念建立网络模型的基础上,讨论了各种针对特定传感器网络特点的路由算法。归纳了基于博弈论的无线传感器网络路由算法的设计原则和分类方法。详细比较了这些算法的特点、性能差异和应用范围.最后对无线传感器网络路由算法的研究现状进行了总结,并指出未来的研究重点。     

新的ASON路由实现方案

提出了一种新的基于OSPF的ASON路由实现方案,扩展了波长链路状态公告和网络节点链路状态公告,用于在全网分发波长和网络拓扑信息。实现了拓扑的自动发现和路由信息的可靠分发,并提供了友好的RWA接口以便引入各种RWA算法和动态连接建立信令协议。通过仿真对本方案进行了验证,比较了若干RWA算法的性能,分析了两类路由信息更新触发策略和在全网分发波长信息的可行性。     

FIRE: flexible intra-AS routing environment

Current routing protocols are monolithic, specifying the algorithm used to construct forwarding tables, the metric used by the algorithm (generally some form of hop count), and the protocol used to distribute these metrics as an integrated package. The flexible intra-AS routing environment (FIRE) is a link-state, intradomain routing protocol that decouples these components. FIRE supports run-time-programmable algorithms and metrics over a secure link-state distribution protocol. By allowing the network operator to dynamically reprogram both the properties being advertised and the routing algorithms used to construct forwarding tables, FIRE enables the development and deployment of novel routing algorithms without the need for a new protocol to distribute state. FIRE supports multiple concurrent routing algorithms and metrics, each constructing separate forwarding tables. By using operator-specified packet filters, separate classes of traffic may be routed using completely different routing algorithms, all supported by a single routing protocol. This paper presents an overview of FIRE, focusing particularly on FIRE's novel aspects with respect to traditional routing protocols. We consider deploying several current unicast and multicast routing algorithms in FIRE, and describe our Java-based implementation     

Topology based placement of multicast capable nodes for supporting efficient multicast communication in WDM optical networks

Most existing algorithms for the problem of optical signal splitter placement or multicast splitting-capable node placement in a WDM network are based on the performance of attempting a large set of randomly generated multicast sessions in the network. Experiments show that placement of multicast capable nodes based on their importance for routing one set of multicast sessions may not be a right choice for another set of multicast sessions. In this work, we propose placement algorithms that are based on network topology and the relative importance of a node in routing multicast sessions, which is measured by our proposed metrics. Since a network topology is fixed once given, the proposed algorithms are essentially network traffic independent. We evaluate the proposed placement algorithms given static sets of multicast sessions as well as under dynamic traffic conditions, which are routed using our splitter constrained multicast routing algorithm. Our results show that the proposed algorithms perform better, compared to existing algorithms.     

基于机器学习的光网络路由与频谱分配机制研究

对于光网络而言,路由与频谱分配是制约光层资源利用率和光网络容量的重要问题之一。机器学习迅速发展,为光网络管理与控制的智能化、自动化提供了新的发展方向。本文回顾了近年来基于机器学习的路由频谱分配相关研究,介绍了光网络控制中常见的机器学习算法,描述了基于神经网络和强化学习的路由频谱分配机制,最后分析了当前研究在泛化性和可靠性等方面的潜在挑战。