一种虚拟路由冗余协议负载均衡技术实现机制

标准VRRP（虚拟路由器冗余协议）解决在配置默认网关环境下消除网络单点故障问题,其协议自身不够灵活,即虚拟路由器中只有主设备进行流量转发,其他备用设备均作为备份不进行流量转发,无法负载分担,不能最大程度提高带宽和设备利用率。针对该局限,在此基于与某公司的合作项目,论述了一种虚拟路由冗余协议负载均衡实现机制,在标准VRRP协议分析研究基础上引入虚拟转发器和转发状态机,实现一个虚拟IP对应多个虚拟MAC的机制,无需配置多个备份组就能同时实现路由冗余备份和流量负载均衡,使局域网内用户能够通过每台虚拟转发器与外界通信,极大地提高资源利用率,最后以实验验证了设计可行性。     

如何利用虚拟转发器实现基于VRRP协议的负载分担

VF(虚拟转发器)的实现能够极大地弥补VRRP(虚拟路由冗余协议)只提供虚拟网关冗余备份,而不能实现流量的负载分担这一缺憾.着眼于VF的研究和实现,并通过科学的软件设计和测试流程得到数据,证明VF的实现,以及能够完成流量负载分担功能.     

VRRP协议实现园区网的高可用性

VRRP协议是FHRP首跳冗余协议的一种,该协议是由IETF于1998年提出的标准协议,并于2005年在RFC3768中更新,主要用于提供园区网中路由的冗余性,VRRP协议使用一种选择机制,使多台路由器形成一个虚拟路由器组,并且通过选举机制选择出一台主用路由器来处理实际数据流的转发,当主用路由器出现故障,虚拟路由器组中的备用路由器将自动接替数据转发的工作,从而保证园区网运行的可靠性。     

虚拟路由冗余协议及应用

随着Internet的迅猛发展，基于网络的应用逐渐增多。这就对网络的可靠性提出了越来越高的要求。斥资对所有网络设备进行更新当然是一种很好的可靠性解决方案；但本着保护现有投资的角度考虑，可以采用廉价冗余的思路，在可靠性和经济性方面找到平衡点。虚拟路由冗余协议就是一种很好的解决方案。在该协议中，对共享多存取访问介质（如以太网）上终端IP设备的默认网关(Default Gateway)进行冗余备份，从而在其中一台路由设备宕机时，备份路由设备及时接管转发工作，向用户提供透明的切换，提高了网络服务质量。一、协议概述在基于TCP/IP…     

虚拟容错路由协议分析和改进研究

对现在的虚拟容错路由协议进行了分析,主要是介绍了VRRP和HSRP协议,对VRRP和HSRP分别进行原理介绍和应用分析,在此基础之上发现了这些协议冗余路由在实现容错时存在这物理设备的浪费,提出的改进主要是在VRRP和HSRP的基础上进一步的对这些路由设备充分利用,提出了利用现有线路和技术实现了静态和动态的负载均衡,并与这些标准兼容。这些改进能很好的为现有网络所利用,改善了网络环境。     

最大化网关流量的物联网路由的研究

为了解决现存的路由方案经常依赖于具体的链路探测包估计路由质量,对能量受限的IoT设备而言成本高昂的问题,提出基于虚拟网络估计的物联网路由(VNE-R)方案。VNE-R路由通过虚拟网络估计节点流量,再用流量大的节点构建路由,进而最大化网络流量。利用OMNEET++软件和SWIM工具进行仿真实验,实验数据表明,VNE-R路由能够较准确地估计各节点的流量并且能够有效地提高网络吞吐量。     

VRRP应用研究

VRRP(Virtual Router Redundancy Protocol)虚拟路由冗余协议,能解决局域网主机访问外部网络的可靠性问题。通过以华为S9300系列交换机为载体,给出了如果配置VRRP来实现提高局域网访问外部网络的可靠性。     

一种基于DVSR和GRE的MPLS VPN中冗余路由的实现

随着多协议标记交换虚拟专用网(MPLSVPN)业务应用的不断发展,越来越多的用户需求不断被提出。其中,对中心节点链路进行冗余,以提高对VPN的可靠性和可用性的需求尤为突出。文中主要对目前的MPLSVPN和现有的动态验证静态路由(DVSR)技术进行分析,再结合客户端(CE)通用路由封装隧道(GREtunnel)内运行开放最短路径优先(OSPF)动态路由技术,实现在目前主流应用的MPLSVPN三层全网状虚拟专用网(Full-MeshVPN)中,利用网络设备的特性和功能来满足用户对冗余路由的需求。     

中继增强的LTE-A系统中路由选择算法的研究

LTE-Advanced系统中引入了中继技术,主要用来扩大小区覆盖尤其是为小区的边缘用户提供较高的服务质量。引入中继节点后,对于终端来说可以根据不同的路由选择策略来接入基站或者中继节点。传统的路由选择策略是基于下行链路性能最优选择相应的接入点,而并未考虑上行链路的性能,对于有些对上行链路质量要求较高的业务并不适合。因此在文章中通过联合考虑上行链路和下行链路,提出一种新的路由选择策略。仿真结果表明,新提出的路由选择策略能保证上行链路吞吐量增大,但是对下行链路的性能影响较小,使系统的整体性能进行提升。     

基于数据融合的无线传感器网络路由算法

在分簇协议LEACH和链状协议PEGASIS的基础上,提出一种新的基于数据融合的分簇路由算法.簇首节点采用多跳方式传输数据,并根据周围节点的密集程度构造不同大小的簇;簇内节点计算上行和下行节点构造数据融合树,采用时分复用调度算法进行多跳路由.NS2仿真结果表明该路由算法均衡了各个节点的能量消耗,延长了网络存活时间,并降低了网络延迟.     

Ad hoc网络中基于数据流的QoS路由协议

已有ad hoc网络中的QoS路由都是基于目的地址的选路并预留资源,当源节点针对同一个目的节点先后建立两个或者多个实时业务流的时候,将导致几个数据流争用资源,使得几个流的QoS都无法得到保证。针对这个问题,文章提出了基于流的QoS路由机制,并且进行了仿真分析,仿真结果表明这种机制能够解决这个问题,使QoS得到保证。     

基于高性能包处理架构VPP的带内网络遥测系统

面向高性能虚拟网络转发架构及设备VPP,通过重构数据平面的流水线处理模块,设计了基于矢量数据包处理技术的带内网络遥测方案,并在此基础上通过引入源路由机制引导遥测报文走向,实现了一种带内全网遥测的扩展案例。最后,基于虚拟机组网方式,搭建网络拓扑并进行网络性能评测。实验结果表明,该遥测系统能够在0.13 ms精度的遥测时间间隔下覆盖被测网络链路,并能以较小代价实时监测虚拟网络的链路拥塞情况。鉴于虚拟网络设备已在数据中心内被广泛部署,该方案通过高精度的虚拟网络测量覆盖,有望为数据中心内多租户网络和网络功能虚拟化的大规模部署提供可靠性保障。     

SEAL2: An SDN‐enabled all‐Layer2 packet forwarding network architecture for multitenant datacenter networks

This paper presents the design and development of a new network virtualization scheme to support multitenant datacenter networking (MT‐DCN) based on software‐defined networking (SDN) technologies. Effective multitenancy supports are essential and challenging for datacenter networking designs. In this study, we propose a new network virtualization architecture framework for efficient packet forwarding in MT‐DCN. Traditionally, an internet host uses IP addresses for both host identification and location information, which causes mobile IP problems whenever the host is moved from one IP subnet to another. Unfortunately, virtual machine (VM) mobility is inevitable for cloud computing in datacenters for reasons such as server consolidation and network traffic flow optimization. To solve the problems, we decouple VM identification and location information with two independent values neither by IP addresses. We redefine the semantics of Ethernet MAC address to embed tenant ID information to the MAC address field without violating its original functionality. We also replace traditional Layer2/Layer3 two‐stage routing schemes (MAC/IP) with an all‐Layer2 packet forwarding mechanism that combines MAC addresses (for VM identification and forwarding in local server groups under an edge switch gateway) and multiprotocol label switching (MPLS) labels (for packet transportation between edge switch gateways across the core label switching network connecting all the edge gateways). To accommodate conventional IP packet architecture in a multitenant environment, SDN (OpenFlow) technology is used to handle all this complex network traffics. We verified the design concepts by a simple system prototype in which all the major system components were implemented. Based on the prototype system, we evaluated packet forwarding efficiency under the proposed network architecture and compared it with conventional IP subnet routing approaches. We also evaluated the incurred packet processing overhead caused by each of the packet routing components.     

Hybrid routing in ad hoc networks with a dynamic virtual backbone

Virtual backbone routing (VBR) is a scalable hybrid routing framework for ad hoc networks, which combines local proactive and global reactive routing components over a variable-sized zone hierarchy. The zone hierarchy is maintained through a novel distributed virtual backbone maintenance scheme, termed the distributed database coverage heuristic (DDCH), also presented in this paper. Borrowing from the design philosophy of the zone routing protocol, VBR limits the proactive link information exchange to the local routing zones only. Furthermore, the reactive component of VBR restricts the route queries to within the virtual backbone only, thus improving the overall routing efficiency. Our numerical results suggest that the cost of the hybrid VBR scheme can be a small fraction of that of either one of the purely proactive or purely reactive protocols, with or without route caching. Since the data routes do not necessarily pass through the virtual backbone nodes, traffic congestion is considerably reduced. Yet, the average length of the VBR routes tends to be close to optimal. Compared with the traditional one-hop hierarchical protocols, our results indicate that, for a network of moderate to large size, VBR with an optimal zone radius larger than one can significantly reduce the routing traffic. Furthermore, we demonstrate VBR's improved scalability through analysis and simulations.     

IP layer restoration and network planning based on virtual protection cycles

We describe a novel restoration strategy called virtual protection cycles (p-cycles, patents pending) for extremely fast restoration in IP networks. Originally conceived for use in WDM and Sonet transport networks, we outline the adaption of the p-cycle concept to an IP environment. In an IP router-based network, p-cycles are implemented with virtual circuits techniques (such as an MPLS label switched path, or other means) to form closed logical loops that protect a number of IP links, or a node. In the event of failure, packets which would normally have been lost are encapsulated with a p-cycle IP address and reenter the routing table, which diverts them onto a protection cycle. They travel by normal forwarding or label switching along the p-cycle until they reach a node where the continuing route cost to the original destination is lower than that at the p-cycle entry node. Diverted packets are deencapsulated (dropped from the p-cycle) at that node and follow a normal (existing) route from there to their destination. Conventional routing protocols such as OSPF remain in place and operate as they do today, to develop a longer term global update to routing tables. Diversionary flows on the p-cycle inherently cease when the global routing update takes effect in response to the failed link or node. The p-cycle thus provides an immediate real-time detour, preventing packet loss, until conventional global routing reconvergence occurs. The aim of the paper is to explain the basic p-cycle concept and its adaptation to both link and node restoration in the IP transport layer, and to outline certain initial results on the problem of optimized design of p-cycle based IP networks.     

A novel IP with MPLS over WDM-based broad-band wavelength switchedIP network

This paper presents a new technology for constructing IP over photonic systems. An IP with multiprotocol label switching (MPLS) over wavelength division multiplexing (WDM)-based broad-band IP network architecture and protocol is proposed and analyzed in this paper, which supports variable-length IP-like optical packet label switching and optical virtual path routing. This system tries to merge into one layer the functionalities of the wavelength switching, SONET mux/demux, and IP routing, and is sometimes known as the concept of optical MPLS. The label banding, forwarding/switching process, and node architecture of the proposed network are discussed and studied. A unique as well as important function of a lambda/label edge router (LER) is a flow assembly device that can encompass MPLS' forward equivalence classes, label stacking, and label switching path aggregation function. At the same time, a particular function of the core label switching router is wavelength merging. A fiber delay line is used to delay the data stream in order to process the label information and resolve contention. Transmission bit error rate measurements of the baseband data stream and back-to-back is also demonstrated to show its feasibility     

在ATM网络中采用业务流自适应分布优化控制的拥塞概率分析

本文提出了一种降低ＡＴＭ网络拥塞率的业务流量分布自适应优化控制方法,建立了一种碰撞函数型的新的距离测度,并建立了多种业务环境下拥塞概率的分析模型,得出了多端口拥塞的计算公式,研究结果表明,业务流量分布的自适应优化控制技术能很好的改善ＡＴＭ网络内的业务流量分布,大大降低了信道拥塞率。     

Load balance in hierarchical routing network

In this article, the problem of load balance in hierarchical routing network is studied. Since conventional shortest path first (SPF) algorithm over aggregated topology in hierarchical routing network may result in worse routing performance, a traffic sharing path selection algorithm and a variable weight scheme are put forward for hierarchical routing network, which can equilibrate the utilities of link resources and reduce the blocking probability of connections with the improvement on survivability. Simulations are conducted to evaluate proposed variable weight and traffics balance (VWTB) algorithm, which combines traffic sharing and variable weight. From the simulation results, it can be found that the proposed VWTB algorithm can balance the traffics and equilibrate the utilities of link resources significantly.     

Active routing

Active routing permits individual customers, network managers, or network owners to control the paths that their data takes through the network. The objective is to allow routing mechanisms that provide quality of service (QoS), mobility, etc., to be quickly deployed, without waiting for standards, and to allow different routing mechanisms, that provide similar services, to compete. The current work on label switching (MPLS) can also be used to give high level customers, such as virtual private networks (VPNs), more control over their paths. We show how active routing can extend the capabilities of MPLS. We address several implementation issues, including pricing and distributed sandboxes. Pricing or policing must be used to limit the resources that customers acquire, in order to encourage them to use network resources economically. Sandboxes must be used to limit the resources that the participants acquire, in order to limit the harm that they can inflict on other participants. Active routing creates a free market system where network providers compete to sell their resources and implementers compete to sell their active routing programs. We establish a framework to quantitatively compare networks and service providers. As an example, we route Internet protocol (IP) telephony over combinations of circuit and packet networks     

Stability-Based RREQ Forwarding Game for Stability-Oriented Route Discovery in MANETs

In traditional stability-oriented route discovery of mobile ad hoc networks, in-between nodes need to rebroadcast identical route request (RREQ) packets, which contain same source node ID and broadcast sequence number, to discover more stable route, yet it increases routing overhead and data transmission delay obviously. Therefore, a stability-oriented route discovery algorithm is proposed to limit routing overhead and decrease transmission delay. In this algorithm, all neighbor nodes of some node will play a mix strategy game named stability-based RREQ forwarding game after receiving an identical RREQ, and independently determine the RREQ forwarding probability based on Nash equilibrium, respectively. The simulation results show that the proposed stability-oriented route discovery algorithm not only reduces routing overhead and transmission delay effectively, but also improve other routing performance.