基于区分服务的IP QoS控制技术

为了提供服务质量保证和支持实时应用,传统IP网络的服务模型已经被扩展,区分服务模型是其中重要的一种。本文首先概述了基于区分服务的IP QoS的控制技术,在此基础上介绍了一种使用QoS管理器和反馈功能控制QoS的体系结构。该结构的标记器和整形器/策略器的参数受来自计量器反馈的影响,并且QoS管理器能够使管理员动态地调整控制参数。     

IP网络QoS实现技术研究

文章主要研究基于多协议标记交换(MPLS)技术和区分服务(DiffServ)／资源预留协议(RSVP)结合模型的IP网络服务质量(QoS)实现技术。首先根据带宽代理(BB)模型给出一种简化的QoS体系结构，然后着重讨论该结构中的4个主要模块：RSVP模块、DiffServ模块、MPLS模块和BB控制模块。在ns-2．26上的仿真表明，该方案有效地改善了丢包率和时延这二个QoS性能指标。     

VoIP业务QoS性能及其优化研究

简要介绍了VoIP传输的基本原理,对影响VoIP业务QoS性能的3个主要因素(时延、抖动和丢包)进行分析,提出了利用MPLSdiffserv awareTE(流量工程)集成模型进行端到端QoS性能优化的方法。MPLSdiffserv awareTE能够感知CoS(服务等级),并根据CoS细粒度来预留资源,在每个CoS级别提供MPLS容错机制,能够为VoIP业务提供低丢失、低延迟、低抖动以及确定的带宽服务,很好地满足服务质量要求。     

IP网服务质量问题的研究

介绍了QoS的综合服务、区分服务和MPLS等几种IP QoS方面技术及其体系结构，并对它们的优缺点进行了比较。最后简单探讨了流量工程和Internet QoS服务方面还需研究的问题。     

IP网络中的QoS研究

本文简要介绍了IETF建议的综合服务(Int-serv)／RSVP、差分服务(Diff-Serv)、多协议标记交换MPLS、业务流量工程TE等几种IP网络QoS保证方案的工作原理，并介绍了流量管理的过程和MPLS流量管理的概念。     

IMS体系结构中的QoS问题

完整的服务质量(QoS)解决方案是通信网络融合中的重要课题,引入基于IP多媒体子系统(IMS)框架的、具有QoS保证的资源控制架构是解决融合网络QoS问题的重要方法.本文在介绍基于综合服务与区分服务相结合的IMS QoS服务模型的基础上,详细讨论IMS网络中的QoS控制结构、资源控制和QoS授权等问题.     

VOIP业务以及相关QoS性能的网络优化研究

简要介绍了VOIP传输的基本原理、传输机制,以及对影响VOIP业务QoS性能的3个主要因素 (时延、抖动和丢包率)进行分析,提出了利用MPLS、diffserv-aware TE(流量工程)集成模型进行端到端QoS 性能优化的方法和解决办法。MPLS、diffserv-aware TE能够感知CoS(服务等级),并提供根据CoS细粒度来预留带宽资源,在每个CoS级别提供MPLS容错的机制,能够为VOIP提供低丢失、低延迟、低抖动以及确定的带宽服务,很好地满足服务质量的要求．     

IP网络服务质量的实现

随着三网融合步伐的不断加快，IP网络的服务质量(IP QoS)受到了广泛的重视。如何合理利用IP网络的有限带宽，保证网络的Qos，是IP网络成为支撑所有业务的统一平台的关键。首先讨论了IP QoS的基本概念和主要机制，然后详细分析了目前正在研究和实施的几种QoS模型的原理及其相互关系。基于这几种模型各自的优势和不足，探讨了将它们互相结合以更好实现IP QoS的可能方案。     

基于区分服务的IP QoS控制技术

为了提供服务质量保证和支持实时应用,传统IP网络的服务模型已经被扩展,区分服务模型是其中重要的一种。这里首先概述了基于区分服务的IPQoS的控制技术,介绍了一种使用QoS管理器和反馈功能控制QoS的体系结构。该结构的标记器和整形器/策略器的参数受来自计量器的反馈的影响,并且QoS管理器能够使管理员动态地调整控制参数。     

Internet分组网中的QoS机制浅析

本文介绍和分析了Internet分组网中提供QoS机制的四种模型,分别是综合服务模型(IntServ)、区分服务模型(DiffServ)、多协议标签交换模型(MPLS)以及流量控制模型。这四种模型各有其优缺点,因此所适用的范围也不相同。本文介绍了与上述四种模型相关的概念,并对各个模型的基本原理及其特点进行了讨论,并结合目前Internet网络的发展趋势,简单介绍了目前QoS机制在不同网络中的应用情况,以及下一代Internet网络中的QoS保障机制。在文章最后,对QoS体系结构及各种服务模型进行了总结与比较。     

IP QoS中的综合业务和区分业务

IP QoS是现代互联网发展中的一项关键技术。IETF已经定义了几种体系结构以解决IP QoS的诸多问题。介绍了其中的两个主流体系结构：综合业务和区分业务，并提出将二者进行结合，从而为下一代互联网提供更好的IP QoS。     

从公路网的视角看IP QoS

本文从公路网的视角重新认识IP QoS问题,提出了互联网所需要和所能提供的是一种适合的、相对的、统计意义上的IP服务质量保证能力,并分析目前在网络实际应用中有助于改善IP QoS一些方法的成功之处,包括提高网络的硬件通行能力、提供差异化的服务质量保证、提高网络对流量的控制能力,最后讨论公路网对IP QoS下一步研究的一些启示.     

A Bandwidth Control Method Providing Entrance QoS for Multimedia Communication

1 Motivation Nowadays , the QoS provided by the wideband IPnetwork starts at an edge-router and ends at anotheredge-router .Therefore ,the trunk QoSisfinished,suchas RSVP[1]and DiffServ[2].In order to complete theend-to-end QoS,the mechanism of entrance QoS (thebandwidth controller) is introduced. As Fig.1 shows ,if the bandwidth controller circledby the dashed frame is not used,the Ethernet is con-nected with the router directly through 100 Mbit/sbandwidth. Then this router is connect…     

Incorporating QoS into IP Enterprise Network Design

Recent trends in enterprise networks are radically changing the composition of these systems. Instead of having diverse data networks, each of which is dedicated to a single class of applications, corporations are moving to a unified IP (Internet Protocol) Intranet. Traffic demands on these Intranets include delay-sensitive traffic that requires better than the standard best effort service provided by IP networks. As a result, various new technologies and strategies to provide end-to-end Quality of Service (QoS) within IP enterprise networks are being developed and implemented. However, current IP network design methodologies are limited in that they can only design networks providing best effort service or else, a single delay constraint for all traffic. In this paper, we discuss a new design methodology for IP enterprise networks that takes into account the new technologies and techniques that can provide QoS. In particular, we identify and discuss the most crucial design issues that must be addressed when specialized queuing-based QoS strategies are used in the network. We describe the new constraints introduced by the underlying technologies and discuss how these factors affect the formulation of the IP Enterprise Network Design Problem. We then describe some specific features and methodologies that have been incorporated into a network design-planning tool for IP enterprise networks with QoS.     

因特网IP QoS机制及其在UMTS网络中的应用

目前广泛使用的因特网协议(IP)已经成为所有数据业务的传输标准。传统的因特网业务策略(BE策略)不能满足新兴的实时业务的需求,因此有必要引入IPQoS机制来更有效的分配资源。由于第三代通信系统网UMTS需要同时支持非实时和实时业务,而且无线网的资源和设备比固定网昂贵得多,所以IPQoS机制对于无线网络尤为重要。文中首先研究因特网IPQoS机制,然后讨论如何将其应用到UMTS网络中。     

IP QoS标准进展

由于电信级IP QoS是实现多业务网络的关键技术,文章分别介绍了国际上主要标准组织IETF、Internet2、ETSI、ITU-T在IPQoS标准化方面的进展,给出了中国IP QoS的研究现状,阐明了IP QoS的研究前景.     

Architecture for mobility and QoS support in all-IP wireless networks

Mobility management and quality-of-service (QoS) provisioning are the important tasks on the future development of wireless networks. The high host mobility makes these tasks more challenging. In this paper, we propose an architecture which supports both mobility and QoS management in Internet protocol (IP)-based wireless networks. In mobility management, the fast handoff, which the packets are forwarded in advance to the neighboring locations where a mobile node (MN) may move to, is provided to reduce the service disruption. Also, the fast location lookup, which the routing information about a MN is replicated to some routers, is provided to avoid the triangular routing problem incurred by the protocol of mobile IP. In QoS provisioning, we enable the end-to-end QoS guarantee by using the resource reservation protocol (RSVP) signaling. In particular, the RSVP aggregation technique is used to avoid the scalability problem. Also, the technique of passive resource reservation is used to reduce the influence of host mobility on the resource reservation delay. We emphasize the integration of mobility and QoS management in the architecture design. A performance analysis is given to justify the benefits of our proposed architecture.     

Differentiated integrated QoS control in the optical Internet

In order to facilitate convergence of networks and services, this article investigates a new hybrid and integrated QoS control scheme that combines electrical IP layer features with reconfigurable optical layer, and addresses cross-layer design on QoS control in optical Internet (i.e., IP/WDM networks). The proposed integrated QoS control scheme can not only provide appropriate transport service for various types of traffic relating to different service categories in a cost-effective way, but also maintain high flexibility/scalability for integrated services provisioning, which seems to be preferred for QoS provisioning in the next-generation multiservice integrated optical Internet.     

Proportional delay differentiation provision by bandwidth adaptation of class‐based queue scheduling

Supporting quality of service (QoS) over the Internet is a very important issue and many mechanisms have already been devised or are under way towards achieving this goal. One of the most important approaches is the so‐called Differentiated Services (DiffServ) architecture, which provides a scalable mechanism for QoS support in a TCP/IP network. The main concept underlying DiffServ is the aggregation of traffic flows at an ingress (or egress) point of a network and the marking of the IP packets of each traffic flow according to several classification criteria. Diffserv is classified under two taxonomies: the absolute and the relative. In absolute DiffServ architecture, an admission control scheme is utilized to provide QoS as absolute bounds of specific QoS parameters. The relative DiffServ model offers also QoS guarantees per class but in reference to the guarantees given to the other classes defined. In this paper, relative proportional delay differentiation is achieved based on class‐based queueing (CBQ) scheduler. Specifically, the service rates allocated to the classes of a CBQ scheduler are frequently adjusted in order to obtain relative delay spacing among them. The model presented can also be exploited in order to meet absolute delay constraints in conjunction with relative delay differentiation provision. Simulation experiments verify that our model can attain relative as well as absolute delay differentiation provided that the preconditions posed are satisfied. Copyright © 2004 John Wiley & Sons, Ltd.     

IP电信网体系架构刍议

因为现实和演进等原因．电信网络IP化的趋势不可阻挡,IP技术最成功的应用就是Internet,但30多年来Internet已经从教育科研走向了商业化应用,再加上技术和社会进步,相关政策的调整等原因,其核心设计理念“端到端的透明性”面临着严峻挑战,已经成为很多问题(尤其是商业模式和安全问题）的根源。因此,构建IP电信网不应是简单地在现有的IP之上增加业务控制、QoS和安全机制等,而是要更新Internet的设计理念,从体系架构开始重新考虑。