Service convergence using MPLS multiservice networks

Enterprises are increasingly using virtual private networks to interconnect remote sites. Traditionally, service providers have used ATM core networks to deliver layer 2 services such as frame relay, ATM, or TDM private lines, which enterprise customers have then used to build their corporate network infrastructure. Such services account for the majority of data service revenues today. However, pressure has increased on service providers to combine increased flexibility with reduced costs in the context of a highly dynamic telecommunications market. Service providers also need to generate new revenues from their IP network infrastructure, through new opportunities such as IP VPNs and virtual private LAN services, while simultaneously achieving operational efficiencies through the convergence of all of their services on a common MPLS backbone. New access and metro network technologies, such as Ethernet, are also emerging that can be used to deliver these new services to enterprise customers alongside ATM and frame relay access. This must be achieved while also supporting existing technologies such as ATM, which continue to deliver highly profitable services. This article discusses the technical challenges in meeting the often conflicting requirements of delivering both traditional layer 2 services and new layer 3 services on a converged MPLS network. We show how both network and service interworking are required, and how these must operate at the user, control, and management planes to enable profitable services to be delivered over the new converged network. The different solutions being defined in the standards bodies are described, and the distinct scenarios they address are explained.     

Technoeconomic evaluation of the major telecommunication investment options for European players

This article summarizes the major results from European projects drawing final conclusions and recommendations from the technoeconomic evaluation of three telecommunications market studies. It presents an analysis addressing a wide range of crucial telecommunications questions debated today. The business cases are: seamless mobile IP service provision, 3G mobile virtual network operators (MVNO), and fixed networks for broadband IP services. Extensive market analysis has been carried out for modeling demand, penetrations, and tariff structures for new mobile services and broadband services as an input to the business cases. Results show that over a 10-year study period, UMTS business is profitable in most cases for established operators with reasonable market share. The 3G MVNO business case is profitable under typical conditions when MVNO yields about 10 percent penetration, depending on the country type. Provision of fixed broadband services with a fiber to the curb solution is viable in dense urban and urban areas, but not in suburban environments, while fiber to the home is viable only in dense urban areas, despite the selection of protocol (ATM vs. Ethernet). Furthermore, broadband wireless access (BWA) systems, in dense urban and urban areas, show quite promising economic results.     

Network high availability for ethernet services using IP/MPLS networks

Enterprises are increasingly using Ethernet as the foundation for transforming their networks to Internet Protocol. Simultaneously, service providers are deploying Ethernet to exploit the demand for wide-area Ethernet services and as the infrastructure for new residential services such as IPTV. This is due to Ethernet's low cost per bit and ubiquity in local area networks. Recent years have seen the widespread deployment of IP/MPLS networks to address this opportunity. IP/MPLS enables enhanced flexibility over the same converged network for IP and legacy services, avoiding the need to build separate per-service networks. It also adds carrier- grade capabilities such as quality of service, traffic engineering, and resiliency, thereby enabling new multipoint services such as virtual private LAN service. However, using Ethernet for ";always-on"; and other mission-critical services has resulted in new resiliency requirements, in both the access and the network core. Two novel developments address these high expectations by enabling significant improvements in service availability. These are pseudowire redundancy and Ethernet multi-chassis link aggregation. This article reviews the current redundancy mechanisms typically deployed in Ethernet and MPLS networks. We show how additional enhancements are required in both the network core and the access to the Ethernet service. We describe new pseudowire redundancy and MC- LAG mechanisms, showing how they work together to enable end-to-end protection for Ethernet virtual private wire services and VPLS.     

基于MPLS的VPLS技术分析

VPLS是一项利用MPLS实现跨域广域网提供LAN业务的技术，它使得在基于包交换的网络架构上．可以实现多点服务，适应了网络发展的需要。从各个角度出发介绍了VPLS的原理、关键技术，在文章的最后，还给出了一个具体的网络实例来进一步解析VPL5的机制。对于要想了解VPLS的读者而言，具有一定的参考价值。     

Ethernet-based public communication services: challenge and opportunity

Enterprises and residential customers increasingly take advantage of more sophisticated applications and evolve their business models. At the same time service providers face declining revenues from existing connectivity services. SPs respond to these trends and start to offer highly customized, high-bandwidth network services that complement and interwork with their existing leased line, ATM, or frame relay offerings. Ethernet is quickly becoming the customer UNI of choice. Ethernet, being a packet-based technology, complements IP-based services such as content, voice, data, video, and additional value-added services over a high-speed access connection. Ethernet also provides a flexible high-speed connection to the SP network and eliminates access bottlenecks. Using Ethernet as the common access interface, providers can employ flexible transport services that enable additional value-added services at layer 3 and above. At the same time the rollout of Ethernet services also challenges the installed base, given that bandwidth per customer is usually much higher and additional attributes for tight SLAs apply. This calls for an updated approach to network deployment and rollout: networks need to be planned and built in a service-centric fashion. Starting with a brief look at the driving forces for Ethernet-based public communication services, this article identifies five generic services for Ethernet MANs/WANs and discusses related deployment issues of the different service options, such as the degree of customization, geographic reach and bandwidth profile of the service, as well as evolution aspects of the installed base.     

Multi-Protocol Label Switching as the Basis for a Converged Core Network

This paper addresses the requirements and issues surrounding the carriage of existing and future services over a multi-protocol label switching (MPLS) core network. It provides an overview of MPLS, describing how MPLS is already being used to support VPN services offering support for multiple qualities of service. It discusses the requirements of future core networks and assesses how MPLS can be used to meet them. Finally it identifies a number of areas where BT is actively working to enhance the capability of MPLS to support future multiservice core network architectures.     

The Broadband Access Facility

The deployment of broadband access networks will revolutionise many aspects of society in the early years of the next millennium. Manufacturers, telecommunications providers and cable television operators world-wide are investing heavily on research into networks that provide broadband multimedia services to customers. BT has developed a prototype of a full service access network that can connect customers via optical fibre, digital subscriber line or radio technologies. This paper describes the physical implementation of the prototype network and the wide range of services that it can support.This prototype network, referred to as the 'broadband access facility' is enabling BT and its partners to understand the best access architectures for a given environment through practical testing. The network now serves as an experimental platform, that can be used for communicating broadband concepts, designing operational processes, developing management solutions and testing advanced applications.The full service access networks (FSAN) initiative is a collaboration involving fourteen of the world's leading telecommunications network operators and major equipment manufacturers. Its vision is to create a shared requirements specification for access systems supporting narrowband and broadband services. This common specification will mean that broadband network components can be developed for world markets, thus raising volumes and driving down unit costs. The common system specification is based around an ATM/SDH (asynchronous transfer mode/synchronous digital hierarchy) core network, with local optical fibre distribution via an ATM PON (passive optical network). DSL (digital subscriber line) systems maximise reuse of existing copper plant. The exact DSL system used depends upon where the optical system is terminated, e.g. in the local exchange, cabinet, kerb or home. Hence this broadband access system can support a range of access architectures — this flexibility is fundamental to the consensus achieved in FSAN.     

Emerging high-speed xDSL access services: architectures, issues,insights, and implications

High-speed asymmetric and symmetric digital subscriber line loop access systems, designed by numerous computer networking and telecommunications equipment companies, are currently the focus of technical trials, market trials, and commercial services deployment around the world. This is to provide millions of residential and business customers worldwide with high-speed always-on connectivity to the Internet, corporate intranets, and various online services. It is estimated that over 460 million copper loops worldwide could potentially be equipped end-to-end with xDSL access systems. Large-scale deployment of broadband access systems offering always-on connectivity to the global Internet and corporate intranets is seen as a key enabler of the bold vision articulated worldwide to utilize open Internet protocols and emerging technologies such as Java to create a unified software-defined (IP) global networking infrastructure. Such a networking platform would serve as a de facto medium for generation and delivery of integrated multimedia content, and revolutionize the way people around the world learn, do business, and interact with each other     

PON网络承载集团客户专线的建设方案

随着集团客户专线业务的大力发展,传统接入技术已很难满足新业务的需求。本文在对比传统接入技术和PON技术的基础上,提出PON网络是解决集团客户专线的最佳实践,并给出不同业务需求下的PON接入方式建设策略。     

我国宽带接入市场发展展望

目前各种宽带接入技术层出不穷,且各具特色,究竟哪种技术会成为未来宽带接入的主流,不同的国家和运营商会有不同的选择。我国的宽带接入市场中,以太网接入市场份额最大;ADSL因Internet的发展而快速崛起;宽带无线接入的市场也即将启动。     

GPON技术在移动网络中的研究

无源光网络一直被认为是光接入网中颇具应用前景的技术,它打破了传统的点到点接入方法,在解决宽带接入问题上是一种经济的、面向未来多业务的用户接入技术。目前用于宽带接入的PON技术主要有ATM PON、Ethernet PON、和GPON。随着因特网的快速发展和以太网的大量使用,针对APON标准过于复杂、在传送以太网和IP数据业务时效率低和EPON无法对传送实时业务提供高质量保证、缺乏电信级的网络监控等缺陷,由FSAN组织在2002年9月提出了具有高速率、高效率、支持多业务传输的吉比特无源光网络GPON。伴随着通信业务形式的改变,用户对整个通信网络的要求越来越高。作为最新技术的GPON能比较好地满足接入网的要求,有望成为下一代网络系统的主要接入技术。     

Local loop unbundling in the Italian network

Unbundling consists of the possibility for a new operator to have special access to an incumbent's network infrastructure in order to provide value-added services without the necessity to duplicate the infrastructure itself. Local loop unbundling has received the most attention in Europe and in Italy. Most Italian operators are interested mainly in physical access to copper loop, which gives the opportunity to offer broadband services pervasively by exploiting the capabilities of xDSL technology. Technical issues to be faced in offering these services are severe and include loop qualification, interference evaluation, and shortage of available loops. Nonetheless, the Italian case, where more than 20 incoming operators are planning to deploy services on unbundled local loops, demonstrates that this opportunity can be a major driver for the development of the broadband services market.     

A review of the technical options for evolving FITL to supportsmall business and residential services

Fiber in the loop (FITL) is being implemented in many countries for telecoms services, with fiber directly entering larger business premises. Fiber already serves DLC's, remote concentrators and street multiplexers at the 600-home level for customers and buildings requiring lower numbers of lines. Transport of video over fiber is becoming commonplace, now serving less than 2400 homes. This paper considers scenarios for fiber to penetrate further into the local loop by reviewing access service requirements and some FITL issues. It highlights enabling technologies for telecoms and video services and options for operators to roll out future services using FITL systems     

AT&T's MPLS OAM architecture, experience, and evolution

This article provides an overview of AT&T's MPLS OAM architecture, and gives examples of operational experience. Hallmarks of the architecture are a single, converged, and integrated MPLS/optical network, and the evolution to fully automated, zero-touch network operation. The concept of one converged IP/MPLS architecture will reduce operations, development, and capital costs. The concept of zero aims to bring full automation for every human-to-computer interaction currently required for setting up and maintaining network services, delivering services to customers in real time with zero defects and cycle time, and supporting both a network as well as an operational environment with six nines reliability. This approach effectively opens the network to the customer, enabling new levels of customer network management, service creation, and ordering, and empowering enterprise customers with the tools to create their own network services as they transform their own internal networks. In the article we describe AT&T's MPLS-enabled services, the corresponding MPLS operations architecture (including MPLS MIBs), our MPLS OAM operational experience, and MPLS OAM evolution needs for MPLS MIB enhancements and new network capabilities. By applying technologies such as artificial intelligence, self-healing/self-identifying network elements, expert systems, rules-based processes, and automatic speech recognition, the architecture will migrate from a predictive network that monitors, correlates, and recommends action; to an adaptive network that monitors, correlates, and takes action; to a cybernated network that has integrated components that dynamically manage by business rules and policies. We give several examples of how AT&T is already investing in and implementing this future vision, and conclude by challenging network researchers, developers, and key industry players to apply new technologies in fully realizing the operational vision.     

ATM in MPLS-based converged core data networks

Services supported by asynchronous transfer mode account for the majority of data and Internet service revenues generated by carrier networks today. This is based on ATM's ability to support high availability services with quality of service. However, the influences of the Internet and a highly dynamic telecommunications market have raised demands for increased flexibility while controlling costs. Therefore, future carrier networks are likely to continue to be based on established technologies, such as ATM, as well as IP. In many cases, this is achieved through maintaining separate ATM and IP core networks, with the IP network supporting Internet services, while the ATM network continues to support guaranteed services such as private lines, broadband access, and video. In some cases, however, it can be advantageous for a carrier to transport segments of their ATM network over their IP network core; for example, to transport ATM traffic currently carried on leased facilities onto an IP network where the service provider owns the facilities. Developments in IP and MPLS-based traffic engineering and QoS may increase the ability of IP-based networks to support ATM services using MPLS. This article provides an overview of approaches enabling a network based on MPLS that naturally supports IP services to also support ATM services. The drivers and requirements for convergence on an IP/MPLS core network are presented, followed by an overview of the different approaches and associated challenges currently being debated in the standards bodies.     

海外运营商家庭用户发展策略

移动运营商面向家庭用户开展业务创新，很重要的一个因素就是接入带宽。KDDI建设F1TH网络。为家庭用户提供固定移动捆绑的全业务服务；英国H3G在缺乏固定资源的情况下，依靠3G技术实现移动宽带接入，注重移动互联网的发展并实行了包月制资费策略。两种方式均可为我国运营商所借鉴。     

以太专线网络建设模式和选择策略研究

从以太专线网络建设模式及演进出发,结合PTN、PON、MPLSVPN等新技术的发展,探讨全业务运营环境下运营商开展大客户以太专线网络建设的新模式,通过新模式与传统MSTP、MSAP、PDH三种接入方式在可靠性、可管理性、可持续发展性及建设运行成本方面的分析,提出针对不同客户需求的选择策略建议,最后对我国当前以太专线网络建设需注意的问题给出简要结论。     

Multiservice Ethernet access

Ethernet is evolving from its origins in the local area network into a cost-effective and reliable wide area network technology. Market research shows that business customers are moving away from traditional leased lines and selecting Ethernet as the access network technology of choice due to its low cost, simplicity and flexibility. Developments in Ethernet technology are now offering service providers the opportunity to deliver cost-effective carrier class Ethernet services. In particular, a new generation of Ethernet network termination equipment (NTE) is emerging which provides remote management, flexible bandwidth and fault diagnosis while supporting access to multiple services delivered over a single physical connection. This paper describes the advantages and potential cost savings of using Ethernet in the access network. A case study for a city demonstrates significant capital expenditure cost savings and highlights the advantages of using new Ethernet NTEs, which can be up to ten times cheaper than SDH technology, delivering equivalent bandwidth. Remote management and fault diagnosis features can also reduce operational expenditure by avoiding unnecessary site visits. A network architecture is presented which supports delivery of Ethernet services over a combination of circuit-switched and packet-switched domains. New standards which are maturing in the IETF, IEEE and ITU to support Ethernet delivery of interoperable services with carrier class reliability are also discussed.     

MPLS VPN业务在运营商城域网中应用探讨

目前VPN技术在运营商和企业网络中应用逐渐成为主流.随着VPN技术的日益成熟,MPLS VPN在运营商城域网中的应用日益广泛.本文通过MPLS VPN技术原理的基础来阐述业务模型,并以六安移动建设的电子政务专网业务重点介绍企业组网的需求并给出使用MPLS VPN技术构建企业专网的组网方案,对MPLS VPN业务在运营商...     

同步以太网测试方法

得益于移动宽带业务的强劲增长,许多移动网络运营商已经或正在把移动回传网络从传统同步传输(如SONET/SDH和T1/E1)迁移到运营级以太网。传统TDM网络不仅提供数据传输,而且能实现频率同步。这样,原来由TDM网络提供的时钟同步也同样必须在以太网络中实现,并且同步的质量和网络性能不能受到影响。再者,3G/LTE无线网络不仅需要频率同步,还需要时间/相位的同步。所以,在部署前对以太网络各个部件作同步性能的验证就显得非常必要。本文介绍了实现以太网同步的各种方式和原理、同步精度测量面临的挑战。结合IXIA业界领先的同步测试工具Anue 3500,重点对PTP技术中的路径支持设备(如边界时钟和透明时钟)的测试方法进行了探讨。