光网络中基于流量均衡的SRLG分离路由算法

基于共享风险链路组(SRLG,shared risk link group)和流量均衡的概念,研究了光网络抗毁设计中基于流量均衡的SRLO尽量分离路由问题,利用网络流量的实际分布来评价链路和SRLG重要性,提出基于流量均衡的SRIG分离算法TBDR.通过计算机仿真表明,TBDR算法性能优于保护路优先算法,该算法能有效降低网络阻塞率,提高网络资源利用率和网络抗毁能力,达到流量均衡的目标.     

认知无线Mesh网络中满足QoS的高吞吐量安全路由协议

提出了一种综合考虑链路安全、链路冲突、链路可靠度与链路可用带宽的路由判据SIEB。SIEB包括链路安全和链路性能2个方面,在SIEB的链路安全权值计算中,为了抵御各种洞攻击,提出了基于两跳邻居反馈的链路信任值计算方法。在此基础上,提出了链路安全权值计算算法LSWC和链路性能权值计算算法LSPC,提出了分布式满足QoS约束的路由协议SIEBP,SIEBP的目标是：构造安全的路由路径,并且最大化网络吞吐量。仿真结果表明,SIEBP能达到预定目标,构造的路径能抵御黑洞、灰洞、虫洞等攻击,并且获得了较高的网络吞吐量。     

Proactive multipath routing with a predictive mechanism in software‐defined networks

With the growth of network traffic volume, link congestion cannot be avoided efficiently with conventional routing protocols. By utilizing the single shortest‐path routing algorithm from link state advertisement information, standard routing protocols lack of global awareness and are difficult to be modified in a traditional network environment. Recently, software‐defined network (SDN) provided innovative architecture for researchers to program their own network protocols. With SDN, we can divert heavy traffic to multiple paths in order to resolve link congestion. Furthermore, certain network traffics come in periodic fashion such as peak hours at working days so that we can leverage forecasting for resource management to improve its performance. In this paper, we propose a proactive multipath routing with a predictive mechanism (PMRP) to achieve high‐performance congestion resolution. PMRP has two main concepts: (a) a proactive mechanism where PMRP deploys M/M/1 queue and traffic statistics to simulate weighted delay for possible combinations of multipaths placement of all subnet pairs, and leverage genetic algorithm for accelerating selection of optimized solution, and (b) a predictive mechanism whereby PMRP uses exponential smoothing for demand traffic volumes and variance predictions. Experimental results show a 49% reduction in average delay as compared with single shortest routing, and a 16% reduction in average delay compared with utilization & topology‐aware multipath routing (UTAMP). With the predictive mechanism, PMRP can decrease an additional 20% average delay. Furthermore, PMRP reduces 93% of flow table usage on average as compared with UTAMP.     

最小化路径代价和流量均衡模型及算法

流量均衡是流量工程中为避免网络拥塞经常采用的路由优化目标,如何选择路径以使流量达到均衡分布是流量路由的研究热点和难点.为了最小化网络拥塞,该文在指出网络拥塞决定于流量路由时所选路径的拥塞特征后,建立了流量分布的最小化路径代价和模型.在流量路由选择路径时,提出基于瓶颈链路的最小代价路径路由算法.在实际的网络拓扑和流量矩阵数据基础上对所提模型及算法进行了实验验证,结果显示:在网络负载较大时最大链路利用率相对于已有模型可降低近20%.     

Dynamic routing of restorable bandwidth-guaranteed tunnels using aggregated network resource usage information

The paper presents new algorithms for dynamic routing of restorable bandwidth-guaranteed paths. We assume that connections are requested one-by-one and there is no prior knowledge of future arrivals. In order to guarantee restorability an alternate link (node) disjoint backup (restoration) path has to be determined, as well as an active path, when the connection is initiated. This joint on-line routing problem is particularly important in optical networks and in MPLS networks for dynamic provisioning of bandwidth-guaranteed or wavelength paths. A simple solution is to find two disjoint paths, but this results in excessive resource usage. Backup path bandwidth usage can be reduced by judicious sharing of backup paths amongst certain active paths while still maintaining restorability. The best sharing performance is achieved if the routing of every path in progress in the network is known to the routing algorithm at the time of a new path setup. We give a new integer programming formulation for this problem. Complete path routing knowledge is a reasonable assumption for a centralized routing algorithm, but is not often desirable, particularly when distributed routing is preferred. We show that a suitably developed algorithm which uses only aggregated information, and not per-path information, is able to perform almost as well as one using complete information. Disseminating this aggregate information is feasible using proposed traffic engineering extensions to routing protocols. We formulate the dynamic restorable bandwidth routing problem in this aggregate information scenario and develop efficient routing algorithms. The performance of our algorithm is close to the complete information bound.     

A New Shared Segment Protection Method for Survivable Networks with Guaranteed Recovery Time

Shared segment protection (SSP), compared with shared path protection (SPP), and shared link protection (SLP), provides an optimal protection configuration due to the ability of maximizing spare capacity sharing, and reducing the restoration time in cases of a single link failure. This paper provides a thorough study on SSP under the GMPLS-based recovery framework, where an effective survivable routing algorithm for SSP is proposed. The tradeoff between the price (i.e., cost representing the amount of resources, and the blocking probability), and the restoration time is extensively studied by simulations on three networks with highly dynamic traffic. We demonstrate that the proposed survivable routing algorithm can be a powerful solution for meeting stringent delay upper bounds for achieving high restorability of transport services. This can significantly improve the network reliability, and enable more advanced, mission critical services in the networks. The comparison among the three protection types further verifies that the proposed scheme can yield significant advantages over shared path protection, and shared link protection.     

Performance analysis of optical multicast in a new switching structure

The emergence of new services demands multicast function in optical network.Because of the high cost and complex architecture of multicast capable (MC) node, splitter-sharing switch structure is introduced in which the light splitters are shared by all input signals.To accommodate to this situation, by extending resource ReSerVation protocol-traffic engineering (RSVP-TE) and open shortest path first-traffic engineering (OSPF-TE), a new optical multicast mechanism is provided and the signaling flow and its finite state machine model are given.At the same time, a multicast routing algorithm in splitter-sharing optical network and a changing link weight policy to balance network traffic are proposed.Simulations in NSFNET show no matter with or without wavelength converters, when the number of splitters is 25% of that demanded by traditional MC nodes, the multicast performance has been close to the ideal circumstance.Wavelength converters and changing link weight help much in improving the traffic performance when the number of splitters is adequate.     

基于最小干扰路由的流量工程动态路由算法研究

分析目前流量工程动态路由算法研究现状,以提高网络吞吐量为目标,提出一种改进的流量工程动态路由算法,综合考虑了网络拓扑和流量分布状况,提出分级的链路关键度定义,将流量工程目标有效转化为路径约束。仿真结果表明所提算法性能比Kodialam算法及其它几种典型的动态路由算法好。     

一种新的基于混沌神经网络的动态路由选择算法

针对通信网的路由选择问题,提出了一种动态路由选择的混沌神经网络实现方法。所提出的此方法具有许多优良特性,即暂态混沌特性和平稳收敛特性,能有效地避免传统Hopfield神经网络极易陷入局部极值的缺陷。它通过短暂的倒分叉过程,能很快进入稳定收敛状态。实验证明了本算法能实时、有效地实现通信网的路由选择,并且当通信网中的业务量发生变化时,算法能自动调整最短路径和负载平衡之间的关系。     

基于邮件路径地理属性分析的垃圾邮件过滤算法

提出一种基于邮件路径地理属性分析的邮件过滤算法GEPA（geographic E—mail path analysis）。首先提取邮件命令报文包含的路由信息，并以此为基础构建邮件路径子集；其次采用一种高效的地理属性映射方法进行地理信息映射；接着对路径中节点的地理逻辑关系背离情况进行分析用于过滤垃圾邮件；最后从中国大陆某骨干网边界路由器的一条链路上（该链路跨越地理边界）采集邮件流量以验证算法性能。研究表明，GEPA识别的垃圾邮件约占邮件总量的13．9％，且算法在执行速度和内存开销等方面具有较好的性能，能够满足实时邮件过滤的需求。     

Fuzzy Least-Congested Path Routing and Improved Remote-Path Routing based on Hierarchical Information in WDM Networks

Although routing schemes based on global knowledge make most optimal routing decisions, they will occupy many resources to keep the state information of the network up-to-date. In this work, we describe a fuzzy least-congested path (FLCP) routing algorithm based on hierarchical information. Simulation shows that the blocking probability using FLCP is very near to the blocking probability using the least-congested path routing (LCP) algorithm based on global information. Under heavy traffic load, the FLCP algorithm is superior to the exhaustive algorithm (EA) and the LCP algorithm with unit information cost. The FLCP algorithm provides better routing, even with incomplete information. Thus, the algorithm requires less information of the network, particularly under heavy traffic load. In addition, an improved remote-path routing approach is provided to reduce the blocking probability of connection requests to a node that is many hops away from the source node.     

面向动态拓扑网络的深度强化学习路由技术

针对现有智能路由技术无法适用于动态拓扑的不足,提出了一种面向动态拓扑的深度强化学习智能路由技术,通过使用图神经网络近似PPO(Proximal Policy Optimization)强化学习算法中的策略函数与值函数、策略函数输出所有链路的权值、基于链路权值计算最小成本路径的方法,实现了路由智能体对不同网络拓扑的泛化....     

EPTR: expected path throughput based routing protocol for wireless mesh network

For effective routing in wireless mesh networks, we proposed a routing metric, expected path throughput (EPT), and a routing protocol, expected path throughput routing protocol (EPTR), to maximize the network throughput. The routing metric EPT is based on the estimated available bandwidth of the routing path, considering the link quality, the inter- and intra-flow interference and the path length. To calculate the EPT of a routing path, we first calculate the expected bandwidth of the link and the clique, and then consider the decay caused by the path length. Based on EPT, a distributed routing protocol EPTR is proposed, aiming to balance the network load and maximize the network throughput. Extensive simulations are conducted to evaluate the performance of the proposed solution. The results show that the proposed EPTR can effectively balance the network load, achieve high network throughput, and out-perform the existing routing protocols with the routing metrics previously proposed for wireless mesh networks.     

电力光通信网中风险均衡路由算法研究

在大力发展智能电网的背景下,支撑电网运转的电力光通信网规模日趋庞大,其承载的业务更加多样化.然而电力光通信网的业务路由规划主要以最短路径算法为主,导致电力光通信网存在业务重要度分布不均衡,从而导致网络局部风险过高的问题.针对上述现状,文章采用深度强化学习技术,以网络业务风险均衡为目标,提出了基于强化学习的电力光通信网风...     

M_CSPF: A Scalable CSPF Routing Scheme with Multiple QoS Constraints for MPLS Traffic Engineering

In the context of multi‐protocol label switching (MPLS) traffic engineering, this paper proposes a scalable constraint‐based shortest path first (CSPF) routing algorithm with multiple QoS metrics. This algorithm, called the multiple constraint‐based shortest path first (M_CSPF) algorithm, provides an optimal route for setting up a label switched path (LSP) that meets bandwidth and end‐to‐end delay constraints. In order to maximize the LSP accommodation probability, we propose a link weight computation algorithm to assign the link weight while taking into account the future traffic load and link interference and adopting the concept of a critical link from the minimum interference routing algorithm. In addition, we propose a bounded order assignment algorithm (BOAA) that assigns the appropriate order to the node and link, taking into account the delay constraint and hop count. In particular, BOAA is designed to achieve fast LSP route computation by pruning any portion of the network topology that exceeds the end‐to‐end delay constraint in the process of traversing the network topology. To clarify the M_CSPF and the existing CSPF routing algorithms, this paper evaluates them from the perspectives of network resource utilization efficiency, end‐to‐end quality, LSP rejection probability, and LSP route computation performance under various network topologies and conditions.     

Optimal Link Weights for IP-Based Networks Supporting Hose-Model VPNs

From traffic engineering point of view, hose-model VPNs are much easier to use for customers than pipe-model VPNs. In this paper we explore the optimal weight setting to support hose-model VPN traffic in an IP-based hop-by-hop routing network. We try to answer the following questions: (1) What is the maximum amount of hose-model VPN traffic with bandwidth guarantees that can be admitted to an IP-based hop-by-hop routing network (as opposed to an MPLS-based network), and (2) what is the optimal link weight setting that can achieve that? We first present a mixed-integer programming formulation to compute the optimal link weights that can maximize the ingress and egress VPN traffic admissible to a hop-by-hop routing network. We also present a heuristic algorithm for solving the link weight searching problem for large networks. We show simulation results to demonstrate the effectiveness of the search algorithm.     

一种用于光网络的高效业务疏导辅助图及动态业务疏导算法

利用辅助图,研究了光网络中的业务疏导技术。为解决传统的辅助图存在着模型复杂、波长通道的带宽利用率不高等问题,提出一种新的业务疏导辅助图,能够更有效地利用已有波长通道,避免低效的路由;为了降低动态业务疏导算法的复杂度,提出了一种简化的k最短路径算法,并以此为基础提出了多种疏导策略。仿真结果表明,本文提出的辅助图及其业务疏导算法,可以有效地减少阻塞率。     

弹性光网络中面向任播业务的节能路由算法

为提高数据中心间光互联网络的能效,面向任播业务提出一种具有业务持续时间感知的混合路径传输节能路由算法.为了减少新建光路和工作元器件数量,优先采用单路径传输;若业务阻塞则以传输能耗最小化为目标进行多路径传输.除此之外,引入基于频谱预留的业务疏导策略来降低保护带宽和光收发器的开销.仿真结果表明:与传统节能路由算法相比,所提算法在显著降低网络能耗的同时,有效避免了业务阻塞率的过度增加,实现了网络能耗与性能的平衡.     

多目标的Internet路由优化控制算法

研究通过优化链路权值以控制网络路由来实施流量工程.以网络拥塞最小化和时延最小化为流量工程目标,建立了多目标的全局路由优化数学模型.求解该问题是NP困难的,提出一种混沌群搜索优化算法进行求解.算法采用群局部搜索,利用混沌变量产生一组分布好的初始解,并在邻域搜索进程中应用扩展贪心思想,提高了算法的全局搜索能力.仿真结果表明所提算法能够有效减少由于流量分布不平衡造成的网络拥塞,同时限制长路径,提高了网络性能.     

弹性光网络双重故障下的自适应保护级别算法

为了降低弹性光网络中双链路故障保护下的业务及带宽阻塞率、均衡带宽资源分配,提出了一种双重故障下的自适应保护级别算法。该算法综合考虑传输距离、调制格式等因素,根据链路频谱资源使用状态动态地更新链路惩罚系数,选取最佳路径进行传输,同时根据请求类型及网络空闲资源状态自适应地选择保护方法,为业务提供最大限度的保护。仿真结果表明,在双链路故障下,算法在阻塞率方面取得了较好的性能,同时均衡了网络中各链路上的资源使用。