共查询到19条相似文献,搜索用时 156 毫秒
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给出了DiffServ网络的一种设计与实现,提出了一种有效的资源管理模型。在该模型中,存在一个带宽代理(Bandwidth Broker)同步多个边界节点的接纳控制,负责区分服务网络之间的SLA(Server Level Agreement)协商,进行路由器配置;边界节点使用RSVP协议为集聚流预留资源;RSVP使用预计算QoS路由寻找路径。整个模型不仅综合了已有资源管理方案的优点,而且保持了区分服务网络的可扩展性。 相似文献
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为更好地将移动自组网络用于网络控制系统(NCS),结合NCS的网络特性,提出了一种基于链路信号质量的QoS路由算法。主要QoS机制包括根据接收信号强度选择较稳定的路由;用Hello报文广播节点的预留带宽;中间节点为所有受影响的数据流修复路由、目的节点向源节点广播路由修复报文进行路由修复。NS2仿真表明当节点移动性强时,该QoS路由算法可有效减少网络的平均端到端时延和丢包率,提高控制系统稳定性。 相似文献
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多数Ad hoc网络路由研究聚焦于找到一条连接源和目的节点的路由,而没有考虑网络的QoS需求,一旦数据流量超过了网络所能承受的限度,数据流的传输质量将无从保证。提出了一种AOMDVQ(AOMDV Based on QoS)路由协议,在AOMDV基础上增加了带宽、时延、跳数和优先级等约束条件,使得在路由发起和路由维护阶段满足一定的QoS需求。仿真结果显示,AOMDVQ协议在高速移动状态下其数据包发送成功率、端到端时延等较AOMDV、MP-AOMDV协议有明显改进。 相似文献
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移动AdHoc网络(MANET)支持QoS保证的能力,受限于无线介质的带宽和节点的移动特性。由于节点的移动,网络拓朴频繁发生变化,一旦节点移动,当前的路由就很容易失效,从而造成通讯中断,这种情况就是链路失效。QoS路由是MANET获得端到端QoS保证的第1步。然而,拓朴变化造成的链路失效状况的存在,使得路由的可靠性对于QoS路由而言非常重要。为使链路失效造成的影响最小,找到生存时间长并且可靠性高的路由就显得尤为重要。提出了一种在MANET中支持Oos路由,并能较好解决链路失效状况的方案。该方案定义了一种新机制,在执行时类似表驱路由协议,通过利用主路径上被共享的邻居节点信息,为主路径上各个独立的子路径预备了可替换的路径。 相似文献
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基于测量的连接接纳控制(Measurement—based Connection Admission Control,MBCAC)通过实时的业务流测量从而对新连接请求做出接受与否的决定.MBCAC无须事先了解业务流的流量模型并能根据通过测量得到的数据动态适应网络灸栽的变化,所以近来受到了重视.分析了与接纳控制有关的问题.提出了一种新的MBcAC分类方法,并通过实验比较了几种MBCAC方案的实现复杂性、可扩展性和带宽利用率等.同时,实验结果也显示出了通过测量汇集流的信息计算有效带宽的方法可以在保证服务质量(QoS)的前提下得到较高的网络资源(带宽)利用率. 相似文献
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HAPS-GEO卫星空间IP网络结构及端到端QoS方案研究 总被引:1,自引:1,他引:0
研究了基于临空平台和GEO卫星的空间IP网络一体化结构以及端到端的服务质量(QoS)方案。依据临空平台和卫星通信网络的特点,首先设计了临空平台-GEO卫星空间IP网络的基本结构,进一步分析了各中转节点的处理职能、空间链路组成形式和建立过程。在通信业务的划分基础上,分析了传统IP网络的端到端QoS方案—综合服务(IntServ)和区分服务(DiffServ)的优缺点,结合临空平台-GEO卫星空间IP网络结构特点,提出了IntServ/DiffServ分区结合端到端QoS方案。通过OPNET仿真,分析了网络的 相似文献
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提出了一种适用于区分服务网络的确保服务的动态资源提供方案:基于聚集状态的分布式动态资源管理。该方案在网络节点基于聚集状态进行接纳控制和动态资源预留,不需要核心节点保存单个流的状态,因此,该方案是可扩展的。方案包括一种轻量级动态资源预留协议和网络节点动态资源管理的相关算法,如状态建立、管理和接纳控制决策算法。该方案中,网络节点聚集状态的建立使用了基于实时流量测量的方法,在提供服务质量(QualityofService,QoS)保证的同时,得到了统计复用的增益,提高了资源的利用率,简化了信令协议,也使该方案具有很好的健壮性。 相似文献
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Mei Yang Yan Huang Jaime Kim Meejeong Lee Tatsuya Suda Matsubara Daisuke 《Computer Communications》2005,28(18):2034-2046
This paper proposes a new QoS framework, called the On-Demand QoS Path framework (ODP). It provides end-to-end QoS guarantees to individual flows with minimal overhead, while keeping the scalability characteristic of DiffServ. ODP exercises per-flow admission control and end-to-end bandwidth reservation at the edge of the network and only differentiates service types in the core of the network. In addition, to adapt to dynamically changing traffic load, ODP monitors the bandwidth utilization of the network and performs dynamic bandwidth reconfiguration in the network core based on the monitored bandwidth utilization. Through extensive simulations, the performance of ODP is investigated and compared with that of IntServ and DiffServ frameworks. The simulation results clearly showed that ODP provides end-to-end QoS guarantees to individual flows, which DiffServ can not provide, with much less overhead than IntServ. 相似文献
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Differentiated Service (DiffServ) architecture has been proposed as a scalable QoS architecture for Internet. DiffServ, however, could not control its loads under heavy traffic conditions, and it could not provide strong QoS responses for individual traffic flow. This paper introduces at the edges of a DiffServ domain, a novel two-level admission control scheme, the Fair Intelligent Admission Control (FIAC). At per-class level, FIAC admits traffic according their fairshare and usage while preventing possible congestion within the DiffServ core. At per-flow level, FIAC estimates and allocates the fairshare for each flow within a class.
Simulation results demonstrate that FIAC adheres extremely well to the bandwidth requirements of DiffServ classes while preventing congestion within the DiffServ core. With FIAC's per-flow level enabled, FIAC is able to prevent uncontrolled UDP flows from depriving TCP-controlled flows of bandwidth share when they are aggregated to the DiffServ domain. 相似文献
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Although the Differentiated Services architecture supports scalable packet forwarding based on aggregate flows, the detailed procedure of Quality of Service (QoS) flow set-up within this architecture has not been well established. In this paper we explore the possibility of a scalable QoS flow set-up using a sink-tree paradigm. The paradigm initially constructs a sink tree at each egress edge router using network topology and bandwidth information provided by a QoS extended version of Open Shortest Path First (OSPF), which is a widely used link-state routing protocol. Our sink-tree paradigm dynamically reallocates network bandwidths online according to traffic demands. As a consequence, our paradigm easily supports QoS routing, resource allocation, and admission control at ingress edge routers without consulting core routers in a way that the QoS flow set-up time and overhead are minimized. Simulation results are very encouraging in that the proposed methodology requires significantly less communication overhead in setting up QoS flows compared to the traditional per-flow signaling-based methodology while still maintaining high resource utilization. 相似文献
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This paper presents a practical approach to managing multimedia traffic in DiffServ network, using network monitoring feedback and control. We exploit the flexibility of multimedia traffic and process network level parameters to adapt the traffic according to the current state of the network. The latter is determined based on reports sent by bandwidth monitors installed on each node of a DiffServ Domain. The bandwidth monitors interact with a policy server which, depending on the network state, decides the policy(ies) that should be enforced by the DiffServ network. The implementation of the selected policies typically leads to accepting, remarking, or dropping the multimedia traffic entering the network. Multimedia streams may be assigned different levels of QoS, as interpreted by the marker at the DiffServ edge router and marked according to network state. To achieve such dynamic QoS adaptation for multimedia applications, we have implemented and evaluated a policy-based management system. Performance evaluation shows that multimedia applications adapt better to network conditions using our approach. 相似文献
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Jae-Young Kim James Won-Ki Hong Tae-Sang Choi 《Journal of Network and Systems Management》2001,9(3):267-291
Differentiated Services (DiffServ), which are currently being standardized in the IETF DiffServ working group, is a solution that can provide different qualities of service to different network users. DiffServ aggregates network packets at edge routers and forwards the aggregated packets to core routers with different priorities. In this paper, we propose methods using the SNMP framework for monitoring edge-to-edge traffic aggregates in a DiffServ domain, which consists of a set of DiffServ-enabled routers. In order to manage each DiffServ router, we have analyzed the DiffServ MIB and instrumented it in the router. Further, we propose monitoring behaviors of edge-to-edge traffic aggregates by combining topology and performance information from MIB II and DiffServ MIB. Construction procedures and graphical representation of the edge-to-edge traffic aggregates are explained in detail. We also extend our efforts to implement a DiffServ domain monitoring system that monitors a set of DiffServ-enabled routers and traffic aggregates between every edge router pair. We believe that the proposed monitoring methods can serve as useful building blocks for managing DiffServ networks. 相似文献
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The issue of resource management in multi-domain Differentiated Services (DiffServ) networks has attracted a lot of attention from researchers who have proposed various provisioning, adaptive marking and admission control schemes. In this paper, we propose a Reinforcement Learning-based Adaptive Marking (RLAM) approach for providing assured end-to-end quality of service (QoS) in the form of end-to-end delay and throughput assurances, while minimizing packet transmission cost since ‘expensive’ Per Hop Behaviors like Expedited Forwarding (EF) are used only when necessary. The proposed scheme tries to satisfy per flow end-to-end QoS through control action,s which act on flow aggregates in the core of the network. Using an ns2 simulation of a multi-domain DiffServ network with multimedia traffic, the RLAM scheme is shown to be effective in significantly lowering packet transmission costs without sacrificing end-to-end QoS, when compared to the commonly used static marking scheme. 相似文献
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Ke-PingLong YunLi RodneyS.Tucker Chong-GangWang 《计算机科学技术学报》2004,19(6):0-0
This paper presents a novel framework for IP Differentiated Services (DiffServ) over optical bursts witching (OBS), namely, DS-OBS. The network architecture, functional model of edge nodes and core nodes,the control packet format, a novel burst assembly scheme at ingress nodes and scheduling algorithm of core nodes are presented. The basic idea is to apply DiffServ capable burst assembly at ingress nodes and perform different per hop behavior (PHB) electronic treatments for control packets of different QoS class services at core nodes. Simulation results show that the proposed schemes can provide the best differentiated service for expedited forwarding (EF), assured forwarding (AF) and best effort (BE) services in terms of end-to-end delay, throughput and IP packet loss probability. 相似文献