下一代网络发展新趋势

本文首先给出了下一代网络的主要业务发展需求以及网络总体架构,并将下一代网络区分为业务网络和基础网络,进而分析了业务网络与基础网络的主要发展趋势,包括集中用户数据管理、统一业务管理平台、构建开放业务环境（提供能力开发API以及用户为中心的业务生成环境）、差异化承载控制等,另外还介绍了标识管理（IdM）的当前研究进展。     

华为与Telenor部署全球容量最大的下一代位置归属寄存器项目

华为技术有限公司近日宣布，华为为巴基斯坦Telenor成功部署全球容量最大的下一代位置归属寄存器（HLR）解决方案。华为下一代HLR将服务巴基斯坦Telenor的4000万用户，帮助运营商提升网络效率、简化网络运营，并可向用户提供更有价值的业务体验。     

下一代网络NGN的定义

ITU—T规定，下一代网络NGN（Next Generation Nerwork）的定义为： 以提供电气通信业务为目的，（1）充分活用宽带、能控制QoS的各种传输技术；（2）分组网络；（3）业务功能与传输技术分离；（4）用户可自由选择服务商和业务；（5）支持普通的移动业务，向用户提供一贯的灵活的服务。     

业务驱动下一代电信网

下一代电信网络（NGN）一直是业内人士的热点话题，有些人士是从技术方面探讨下一代网络；也有很多人从性能方面探讨这个问题。UT斯达康认为下一代网络（NGN）是业务驱动型网络。由于基于IP的基础设施支持业务与网络承载的分离，作为在IP基础设施上提供电信业务的关键，软交换技术将在下一代网络中起着核心的作用。一、网络与应用紧密结合 UT斯达康通过对行业和用户市场的深入分析后认为：首先，作为电信的用户，更多的是关心运营商能够提供什么样的服务；其次，作为拥有商业化网络的电信运营商，必须要考虑用有限的资源满足大量用户…     

烽火科技软交换增值业务实现及应用分析

下一代网络（NGN）是业务驱动的网络用户追切需要进行业务创新，众多的运营商也寄希望于软交换能为他们提供新的业务运营模式。目前电信运营商提供的业务大多种类有限模式单一，差异化程度不够，对用户构不成足够的吸弓力，无法刺激用户的消费欲望。电信市场能竞争，说到底是业务的竞争，     

通用引导架构在IMS网络中的应用

IP多媒体子系统（IMS）是第三代标准组织（3GPP）在ReIease5阶段提出的一个开放的网络架构。由于IMS网络具有控制和业务分离、接入无关、统一控制等特点,3GPP、国际电信联盟远程通信标准化组织（ITU-T）等标准组织明确IMS为下一代网络的核心,由IMS提供广泛的基于IP的应用服务。随着业务的开展,业务安全性和用户体验变得越来越重要。     

关于下一代网络(NGN)技术的发展方向研究

NGN是下一代网络的缩写,下一代网络是相对于现在的网络模式来说的,也就是指未来网络.NGN是电信网与因特网等各种网络模式相互竞争导致的结果,网络行业只有竞争才会有所发展.NGN是将传统的各种网络模式进行相互兼容的网络,能够做到无论是在何时何地,用户都能够接入到NGN网络,能够从事所需要的业务活动,能够获得所需的网络信息.下一代网络整合了现在网络的环境,将视频、音频等用户需要融为一体,为用户提供更为便捷的服务.     

知识窗

下一代网络下一代网络(NGN)是可以提供包括话音、数据和多媒体等各种业务的综合开放的网络构架,它采用分层结构实现网络业务、呼叫控制和承载的分离。从业务层来看,下一代网络为传统电信网、移动通信网和Internet等网络提供统一的业务平台,通过各种网络技术的融合和协作,提供比现有各种网络更有竞争力、更加丰富和灵活的业务。下一代网络架构由业务层、控制层、媒体层、接入和传输层等4层组成。其中,接入和传输层负责将用户连接至网络,实现业务量的集中和业务传送功能;媒体层负责将用户送来的信息转换成能够在网上传递的格式并将信息选路…     

立足中国的下一代网络——中兴Softswith支持NGN业务平台建设

随着通信技术的飞速发展和电信市场的逐步开放,电信业的一个最重要的发展趋势就是业务运营商和网络运营商的分离：由网络运营商提供可靠且高效的基础承载平台,由业务提供商提供各种应用。相对于承载系统而言,由于直接面向不同的用户需求,应用系统要复杂得多,这就决定了在下一代网络（ＮＧＮ）中,业务运营商的数量将远远超过网络运营商的数量,其生存和发展则依赖于丰富的业务和应用。因此,下—代通信设备必须能够具有强大的业务提供能力,才能承担起建设集话音、数据、视频等业务于一体的重任。 下一代网络是业务驱动的网络,其功能…     

下一代网络的体系结构及关键技术研究

网络技术的迅猛发展导致网络的异构性问题越来越突出,而各层次用户都要求新网络能够提供更加开放和稳定、高性能、可重用、可灵活定制的服务,这是原来相对封闭的专用服务平台和业务环境所无法提供的。基于各种考虑,下一代网络采用开放的网络架构体系,由业务驱动基于统一协议的分组网络。文中通过研究网络体系结构的演进,得出下一代网络体系结构应具有的特点及发展趋势,并对实现时所要求的关键技术进行了探讨。     

基于ASON的业务提供与管理技术

文章认为自动交换光网络的网络演进必将带动传输网络运营模式和业务提供方式的变化,围绕自动交换光网络的业务提供技术和业务管理技术必将成为下一轮研究的热点,传统光传送网络将向业务光网络的演进.为此文章在分析ASON的业务框架结构和需求的基础上,对ASON新型增值业务提供模式进行了讨论,并提出了一种基于ASON的业务管理框架.     

Securing reliable server pooling in MANET against byzantine adversaries

Reliable server pooling (rSerPool) is an architecture and a set of protocols allowing a service provider to run several servers that can reliably provide the same service. Should a particular server fail while providing its service, another server can efficiently replace it. This property is attractive not only for wired but also for wireless networks. However, the unique characteristics of mobile ad hoc networks (MANETs) bring serious reliability and security challenges to the application of rSerPool. In this paper, we perform a comprehensive investigation of the security of rSerPool in MANET against both server failures and, especially, Byzantine attacks. We formulate security requirements for rSerPool in MANET and design efficient, distributed, and survivable security solutions for both main phases of rSerPool: service discovery and service provision. Specifically, we secure the service discovery phase by using a secure multiple-dominating set creation protocol, and the service provision phase by using a novel type of threshold signature scheme. Both protocols address novel security goals and are of independent interest as they can find applications to other areas; most notably, the construction of a distributed and survivable public-key infrastructure in MANET.     

Per-domain packet scale rate guarantee for expedited forwarding

The expedited forwarding per-hop behavior (EF PHB) was recently replaced by a new definition, called packet scale rate guarantee (PSRG), under the Differentiated Services (DiffServ) framework. This replacement raises two challenges. One is the implementation of a PSRG server. Another is the provision of per-domain PSRG. Specifically, for the former, an open issue is whether hierarchical schedulers can provide PSRG; for the latter, it is not clear whether and how per-domain PSRG can be provided in the presence of flow aggregation. Since, in DiffServ networks, flow aggregation is a natural phenomenon and hierarchical scheduling is high-likely desired, these two challenges become even more critical. To address the first challenge, we introduce a new concept called latency-rate worst-case service guarantee (LR-WSG). We prove that, if a server provides LR-WSG, it also provides PSRG. We show that many well-known schedulers support LR-WSG, which include not only one-level schedulers but also their hierarchical versions. To address the second challenge, we first prove that PSRG can be extended from per-node to per-domain if no flow aggregation is performed. The proof is notable in that it depends solely on the concept of PSRG itself. We then investigate the provision of per-domain PSRG in presence of flow aggregation. We propose to use packet scale fair aggregator (PSFA) to aggregate flows. We show that, with PSFA, per-domain PSRG can be provided in spite of flow aggregation. We finally provide a brief discuss on the viability of using PSFA in DiffServ networks and define an expedited forwarding per-domain behavior (EF PDB).     

An open-systems approach to video on demand

Open systems will enable video servers and set-tops to provide different services in a variety of environments. Hewlett-Packard is interested in applying the principles of open systems to video on demand (VOD). In particular, the company is developing a technology base that will allow their servers and set-tops to operate in a variety of environments and enable the provision of a variety of services. The impact that the different VOD system elements have on the video server and set-top are examined from a communications standpoint. Opportunities for open or standard interfaces are identified and recommendations are made on what these should be where possible     

基于CORBA的移动多Agent框架

随着网络和移动智能体技术的不断发展,如何在网络资源中找到自己需要的服务成为一个热门话题。描述以一种移动的多智能体系统,并且在进行系统底层通信、智能体在网络环境移动、智能体与服务器之间通信应用CORBA。服务器接受任务,派遣服务请求智能体在网络环境中寻找能为自己提供服务的服务器,完成向服务器预订服务任务。给出系统接受任务后派遣请求智能体的工作流程及服务器接受智能体访问的流程。     

A programmable architecture for the provision of hybrid services

The success of new service provision platforms will largely depend on their ability to blend with existing technologies. The advent of Internet telephony, although impressive, is unlikely to make telephone customers suddenly turn in favor of computers. Rather, customers display increasing interest in services that span multiple networks (especially Internet protocol-based networks and the telephone and cellular networks) and open new vistas. We refer to these services as hybrid services and propose an architecture for their provision. This architecture allows for programming the service platform elements (i.e., network nodes, gateways, control servers, and terminals) in order to include new service logics. We identify components that can be assembled to build these logics by considering a service as a composition of features such as address translation, security, call control, connectivity, charging, and user interaction. Generic service components are derived from the modeling of these features. We assure that our proposal can be implemented even in existing systems in return for slight changes. These systems are required to generate an event when a special service is encountered. The treatment of this event is handled by an object at a Java service layer. Java has been chosen for its platform-neutrality property and its embedded security mechanisms. Using our architecture, we design a hybrid closed user group service     

网络安全中的DDos攻击的检测与防御研究 ——以用户访问权益为优先考虑的DDOS防御策略

现代社会,互联网成为了人民生活的基础设施,网络安全就显得尤为重要。DDOS攻击给网络服务的正常运行会带来不可估量的损失,而现有的DDOS攻击防御方法以保护服务器为初衷,使得过度保护而影响了用户使用权益。文章设计并提出在以用户访问权益为优先考虑的情况下,通过网络数据包捕获、分析与功能限制模组、验证码、黑名单四大模块实现,缓解DDos攻击对服务器造成的过大伤害并使服务器维持运行持续提高服务的方法,通过实验可以有效保障服务器运行的同时抵抗DDOS攻击带来的风险。     

On management of CATV full service networks: a European perspective

The CATV network operators hope to offer digital services and evolve their networks to full service networks. There are many hurdles for them at the moment in the transition to a digital network and digital service offering from the current analog-based technology. Key to the success of the transition will be a well-integrated and capable management system to allow CATV operators and service providers to control the network as well as the services they will offer. The CATV operators need to agree on a common data communication infrastructure and plan how their new digital services will be offered to subscribers without disrupting the current customer base of analog service users. The choice of network technology and data communication protocols will have a strong influence on the network management technology chosen. A vital element for the provision of a common open communication architecture as well as for the purposes of network management is that the IP is used. The adoption of existing standards is vital in order to establish a fast route to open network management for CATV networks. It is possible that CATV operators and service providers will have to integrate existing SNMP management systems and TMN/OSI management, with newer integrated service management systems based on TINA and implemented on a CORBA platform. There is a strong need to address security issues before any of these technologies can be deployed for service. There is currently investment (deployed systems and research) which uses each of the technologies mentioned, so these technologies will need to coexist. This article highlights the differences between the North American and European network architectures, and outlines the European network and network management scenario. This is based on the authors involvement in a Pan-European CATV project, Integrated Broadband Communication over Broadcast Networks-IBCoBN     

Discovering the architecture of geo-located web services for next generation mobile networks

As many geo-located Web services will be deployed in the future, mobile clients will be interested in locating a specific application server based on requirements such as proximity, service cost per location area, bandwidth, and server utilization rates. This paper presents a middleware system called GLWSA (Geo-Located Web Services Architecture) that aims to satisfy these requirements in addition to providing a thematic factorization of common location functions in order to locate mobile clients. The GLWSA supports a set of GLWSMs (Geo-Located Web Services Manager) distributed over the mobile network. It defines protocols to discover and inform a Supplier Application Server (SAS) to migrate the service execution (from a specific client) to the nearest SAS based on the client's location. This architecture is suitable to assist mobile clients to discover the geo-located Web services and to maintain the service execution closest to their location.     

基于CDN的可扩展多级视频网格结构研究

针对二级结构的视频网格缺乏可扩展性的缺点,提出利用客户端主机的冗余处理能力,将部分客户端主机当作加盟服务器使用,以降低区域服务器的工作负载.详细论述了多级视频网格体系结构的设计和各服务器的工作模式,以及当加盟服务器突然失效时点播服务的平稳迁移.通过视频网格模拟器VGSim的仿真结果表明,可扩展多级视频网格结构中,区域服务器的工作负载和网络带宽的占用被大大减轻,整个系统的服务能力被有效增强.