基于IXP2400网络处理器的DiffServ系统模型

网络处理器是新一代用采执行数据处理和转发的高速可编程处理器，它代表了未来网络设备设计的发展方向。本文主要介绍了Intel公司推出的网络处理器IXP2400的功能结构，同时详细的介绍了基于IXP2400的DiffServ的实现模型。为以后基于网络处理器的应用开发提供一些借鉴经验。     

基于网络处理器的IPv6路由器研究

网络处理器是下一代网络的关键技术，基于IXP2400的路由器设计正是这一技术的体现，首先介绍IXP2400处理器的性能结构和主要组成部分的功能，然后阐述了基于IXP2400网络处理器的IPv6路由器设计的方案，并着重描述了IPv6路由器数据平面的实现及系统资源分配策略。     

一种基于网络处理器的高性能安全路由器研究

安全路由器是解决网络安全问题的关键设备，可编程的网络处理器解决了安全路由器实现中面临的灵活性、业务丰富能力及可扩展性等难题。本文分析研究了安全路由器的技术体系、IXPl200网络处理器的功能特点．给出了一种基于IXPl200网络处理器的高性能安全接入路由器解决方案。     

DiffServG与MPLS相结合的QoS保障机制

该文分析了IntServ/RSVP与DiffServ这两种IP网络的QoS保障机制的原理，并对这两种体系结构进行了比较，说明了各自的优缺点，同时也指出了这两种机制的适用环境。文中提出了一种将DiffServ模型与MPLS技术相结合的基于IP网络的QoS保障机制。该方案实现简便，无需修改信令协议和中间路由器的功能，只需在标记边缘路由器上进行一定映射即可。利用该方法可以很好地保障IP网络的QoS。     

基于硬件的安全路由器设计和实现

当前的许多安全路由器采用常规路由器硬件平台加安全软件的方式实现，效率低下而不能满足线速安全的需求。针对这一技术缺陷，我们使用通信处理器MPC8260和安全处理器MPC180来设计并实现了一款安全路由器。利用MPC8260提供中央处理以及路由器接口，而MPC180则提供硬件加密功能，解决软件实现VPN功能时效率低下的缺点。通过对设计的硬件平台的测试，表明我们设计的安全路由器能够满足中小企业虚拟私有网络(VPN)应用的需求，具有较好的性能价格比。     

第五代路由器的发展现状与应用前景

第五代路由器的出现和现状 以ASIC为技术体系的GSR的出现，使得路由器的性能大大提高，但是，这种路由器主要满足数据业务(字、图片)的快速转发，不能解决全业务(语音、数据、视频、专线)的传送要求。随着网络规模的扩大，这个矛盾越来越突出，有人意识到了这个问题的严重性。1998年，美国康奈尔(CornelI)大学的S.Keshav和R0sen Sharma在IEEE通信杂志上发表了Issues and Trends in Router Design的论，提出骨干路由器需要在提高性能的同时，解决流识别、简易配置等问题，指明了路由器设计的新潮流。华盛顿大学的Tilman Wolf进一步研究了高性能路由器的设计，发表论，从理论上提出基于网络处理器技术的路由器将能够解决GSR存在的问题，并由此提出下代路由器(第五代路由器)的理念。     

基于网络处理器的服务质量控制

网络处理器以其优异的性价比和高度的灵活性成为目前路由器中实现服务质量控制的最佳硬件选择。首先简要描述了区分服务机制，然后对其微块划分进行了分析。最后。基于Intel公司IXP2400网络处理器的硬件特征对数据存储模块和服务质量控制处理流程做了相应设计，有效实现了基于IXP2400的服务质量控制。     

DiffServ与MPLS相结合的QoS保障机制

该文分析了IntServ/RSVP与DiffServ这两种IP网络的QoS保障机制的原理,并对这两种体系结构进行了比较,说明了各自的优缺点,同时也指出了这两种机制的适用环境。文中提出了一种将DiffServ模型与MPLS技术相结合的基于IP网络的QoS保障机制。该方案实现简便,无需修改信令协议和中间路由器的功能,只需在标记边缘路由器上进行一定映射即可。利用该方法可以很好地保障IP网络的QoS。     

基于策略的域内MPLS流量工程

由于DiffServ和MPLS的良好性能，业界普遍认为DiffServ和MPLS互通是实现流量工程的最佳技术；网络运营商为达到某种商业目的，往往希望在网络中实施策略规则。我们在深入研究Tequila项目成果的基础上，抽象出了在DiffServ网络中基于策略的域内MPLS流量工程系统体系结构，深化了流量工程目标的数学建模，并给出了相关策略。     

中兴通讯高端路由器全面进入铁通全国骨干网

近日，中兴通讯在铁通全国骨干网(CRNet)三期招标中胜出，中兴ZXR10系列高端路由器作为唯一中标的国产路由器产品设备凭借卓越的性能表现和广泛的应用获得了中国铁通的信任和青睐。ZXR10不仅可以全面支持MPLS、多种VPN和多种跨域方式，还可实现基于MPLS的流量工程和DiffServ QoS。     

A flexible and distributed architecture for adaptive end-to-end QoS provisioning in next-generation networks

A novel distributed end-to-end quality-of-service (QoS) provisioning architecture based on the concept of decoupling the end-to-end QoS provisioning from the service provisioning at routers in the differentiated service (DiffServ) network is proposed. The main objective of this architecture is to enhance the QoS granularity and flexibility offered in the DiffServ network model and improve both the network resource utilization and user benefits. The proposed architecture consists of a new endpoint admission control referred to as explicit endpoint admission control at the user side, the service vector which allows a data flow to choose different services at different routers along its data path, and a packet marking architecture and algorithm at the router side. The achievable performance of the proposed approach is studied, and the corresponding results demonstrate that the proposed mechanism can have better service differentiation capability and lower request dropping probability than the integrated service over DiffServ schemes. Furthermore, it is shown that it preserves a friendly networking environment for conventional transmission control protocol flows and maintains the simplicity feature of the DiffServ network model.     

区分服务结构及其TCP性能分析

本文首先对区分服务(DiffServ)结构中的边缘路由器和核心路由器机制进行了系统的分类研究,分析并比较了各种机制.接着,对区分服务结构中TCP的性能问题进行了研究,总结了国内外对这一问题的仿真、解析模型分析和实验研究的成果.找出了关键的问题所在,并根据我们的研究成果提出了一些区分服务结构本身的改进建议.     

Jitter analysis of homogeneous traffic in differentiated services networks

A critical challenge for networking vendors and carrier companies is to be able to accurately estimate the quality of service (QoS) that will be provided based on the network architecture, router/switch topology, and protocol applied. In addition, due to the development of technologies like multiprotocol label switching (MPLS) and generalized MPLS (GMPLS), which can deploy differentiated services (DiffServ), the variation in QoS performance based on the priority assignment is of significant importance. In this focus, this paper provides a theoretical analysis of interarrival packet jitter of homogeneous traffic based on a nonpreemptive head-of-the-line (HOL) priority scheme.     

基于 ForCES的转发件中Xscale层的研究和实现

为了改进目前IP路由器的可扩展性和灵活性等特点,研究基于开放可编程的新一代路由器架构.介绍了控制和转发相分离的ForCES协议框架和Intel IXA结构,提出了一种基于网络处理器IXP2400并支持ForCES协议的开放可编程的路由器框架.详细地分析了转发件中Xscale层的设计和实现.在此基础上设计了相应的测试平台,实验结果表明了这种路由器框架的可行性.     

QoS-IP业务的根本保证

介绍了目前在IP网络上实现QoS的主要架构，并着重阐述了Differv这种主流架构的原理，以及以Alcatel 7750 SR为代表的新一代面向业务设计的网络设备对于QoS的支持能力。     

基于区分服务的边缘路由器的服务质量

Internet real-time multimedia communication brings a further challenge to Quality of Service （QoS）. A higher QoS in communication is required increasingly. As a new framework for providing QoS services, Differentiated Services （DiffServ） is undergoing a speedily standardization process at the IETF. DiffServ not only can offer classified level of services, but also can provide guaranteed QoS in a certain extent. In order to provide QoS, DiffServ must be properly configured. The traditional DiffServ mechanism provides classifier for edge router to mark the different traffic streams, and then the core router uses different Drop Packet Mechanisms to drop packets or transmit data packets according to these classified markers. When multiple edge routers or other core routers transmit data packets high speedily to a single core router, the core router will emerge bottleneck bandwidth. The most valid solution to this problem is that the edge router adopts drop packet mechanism. This paper proposes an Modified Edge Router Mechanism that let the edge router achieve marking, dropping and transmitting packets of hybrid traffic streams based on DiffServ in a given bandwidth, the core router will only transmits packets but won＇t drop packets. By the simulation of ns2, the modified mechanism ensure the QoS of high priority traffics and simplify the core router, it is a valid method to solve the congestion of the core router.     

一种实现LAR协议的路由器架构设计

LAR （Location-Aided Routing）协议是一种适用于无线移动自组网的路由协议.介绍了当前传统的路由器架构,实现LAR协议路由器的需求,并提出了一种实现LAR协议的、基于Linux架构的路由器架构设计.     

基于DiffServ的MIPv6安全接入方案

结合DiffServ网络QoS控制与AAA安全机制,文中设计了一种网络区域边界安全的MIPv6接入方案。方案采用AAA认证授权,实现MIPv6转交地址配置和应用层与网络层身份一一映射,为DiffServ区域提供了边界保护;采用应用层与网络层安全协同,减轻了边界路由安全负荷。     

宽带无线IP系统中基于区分服务的QoS实现策略

讨论了在宽带无线IP系统中实现QoS的问题。提出了一个基于区分服务(DiffServ)的QoS框架,并针对无线链路上的高误码率、窄带宽、性能变化剧烈、用户移动性等特点,对DiffServ进行了加强,并提供了一种针对业务类型的用户接入控制机制。仿真结果显示了该QoS框架的性能。     

All-IP 4G Network architecture for efficient mobility and resource management

In this article, we investigate 4G network architecture and consider two underlying layers: PHY and MAC. We compare two models of wireless access network: pure all-IP and subnet based networks. The pure all-IP model is simple and cost-efficient but causes implementation issues of mobility management and resource coordination. In contrast, the subnet based network enables layer 2 and layer 3 handoffs to be executed independently, deploying several access points under an access router. Further, to handle various cases efficiently according to traffic class and mobility, we present an advanced model of a hierarchical cellular system that combines multiple access techniques of OFDMA and FH-OFDMA with microcells and macrocells. Finally, as an integrated approach to support diverse QoS requirements, we consider an IP-triggered resource allocation strategy (ITRAS) that exploits IntServ and DiffServ of the network layer to interwork with channel allocation and multiple access of MAC and PHY layers, respectively. These cross layer approaches shed light on designing a QoS support model in a 4G network that cannot be handled properly by a single layer based approach