首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
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.  相似文献   

2.
IPTV与目前的3个运营网(有线电视网、Internet和电信网)及其业务直接相关。但不同运营商对IPTV业务有不同定位。电信运营商认为IPTV业务体现于电视节目在IP网中的组织和传送形式,有线电视网络运营商认为IPTV业务是利用有线电视网来提供数字电视节目和电视节目以外的信息服务。由于IPTV业务分为广播业务和交互型业务两大类,支撑这两类业务的承载网也相应地分别采用单向广播网和双向交互网,因而在承载网层很难融合。融合工作将在业务层发生,即充分利用已经存在的两个承载网来经济、高效地发展业务。IPTV中既拥有广播型业务,又拥有组播型业务,还拥有交互型业务,将是三网融合的开端。  相似文献   

3.
Insufficient quality due to packet loss is one of the main obstacles to the broad adoption of IPTV services. However, with the use of end-to- end application layer reliability solutions IPTV services can be enabled over existing IP networks. In particular, application layer forward error correction (AL-FEC) solutions provide a straightforward and powerful means to overcome packet loss. Different solutions for different IPTV service types are introduced and compared. Selected performance results are provided to show the performance and potential of AL-FEC solutions for IPTV applications. From the results it is verified that even in non-perfect transmission conditions IPTV services can easily be deployed without requiring huge investments in new infrastructure and network equipment. Powerful AL-FEC enables high-quality IPTV services without abandoning the promises of the Internet: best effort transport and end-to-end reliability.  相似文献   

4.
Hybrid transport solutions for TDM/data networking services   总被引:1,自引:0,他引:1  
There is a growing demand for native data transport services for enterprises and corporations across public transport networks. Equipment vendors have begun to incorporate a variety of LAN and storage area network interfaces, notably Ethernet, Fibre Channel/FICON, and ESCON, on traditional metro and long-haul transport equipment. Embracing Ethernet and SAN technology enables the introduction of flexible high-capacity transport services optimized for data networking. Transport operators may thus offer both enterprise-centric connectivity services, such as transparent LAN connectivity and virtual LAN services, as well as traditional bandwidth services, such as private lines, while preserving the operations and management infrastructure of the existing public networks. We discuss the benefits of a hybrid Ethernet/TDM transport solution  相似文献   

5.
Wireless Mesh Networks for In-Home IPTV Distribution   总被引:1,自引:0,他引:1  
IPTV is considered to be the next killer application. A key, challenging issue is in-home IPTV distribution with affordable deployment cost and sufficient flexibility, scalability, and reliability. In this article, we first survey and compare the emerging wired and wireless communication technologies for broadband home networks, including transmission over power lines, phone lines, coaxial cables or Ethernet cables, and IEEE 802.1 In, ultra wideband and millimeter wave wireless technologies. Considering these promising candidates for future broadband home networks, we propose three wireless mesh network architectures. These enable consumers to enjoy anywhere, anytime IPTV services without rewiring their homes. We compare the cost, reliability, and scalability of the three architectures. We further study their admission regions for IPTV, that is, the number of IPTV connections that can be supported simultaneously with satisfactory QoS. Analytical and simulation results with H.264 HDTV sources over wired, single hop wireless, and multi-hop wireless paths are given. These results can provide important guidelines for future broadband home network design supporting IPTV services.  相似文献   

6.
Service convergence using MPLS multiservice networks   总被引:2,自引:0,他引:2  
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.  相似文献   

7.
Packet-aware transport for metro networks   总被引:2,自引:0,他引:2  
Today's metro networks have evolved from the need to support traditional voice and private line services. However, the tremendous growth in access to frame relay, ATM, IP, and Ethernet services, coupled with the desire of enterprise customers to interconnect via Ethernet interfaces, suggests the need for a new approach. This article proposes a new architecture for packet-aware transport networks (PATN) that supports both packet and traditional TDM services and leverages an assemblage of emerging technologies to provide efficient aggregation and switching of packet traffic in metro networks. The PATN has the potential to provide significant cost savings to carriers by reducing the number of network elements, reducing transport costs through statistical multiplexing, and eliminating the need for redundant multiplexing operations.  相似文献   

8.
Ethernet-based public communication services: challenge and opportunity   总被引:3,自引:0,他引:3  
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.  相似文献   

9.
New Internet Protocol Television (IPTV) services are including new technologies such as Stereoscopic TV and three‐dimensions (3D) HDTV. As well, increased ubiquitous networking and promoting in smart devices have led to high demand IPTV (over networks). Stereoscopic content required higher data flow to support these emerging TV services, and there are higher requirements at the network layer to provide good quality of service and quality of experience to the end users in delivering stereoscopic IPTV. In this paper, we propose a new concept of cognitive network management algorithm and protocol based on 3D coding techniques for delivering of stereoscopic IPTV service. The proposed approach explains how the management algorithm observes the network performance to guarantee the quality of the stereoscopic IPTV services, by measuring the performance of quality of service (QoS) parameters (delay, jitter, and packets loss) and quality of experience (QoE) metrics such as Peak Signal‐to‐Noise Ratio (PSNR), Moving Image Videography (MIV), and Mean Opinion Score (MOS). Those parameters are monitored in order to take appropriate codification decision for IPTV service provider. Moreover, the codification decision uses K‐mean classification to select the better codification for the end users. Therefore, both kinds of 3D coding formats such as Stereo Video Coding (SVC) format and 2D + Z Coding format (2D‐plus‐Depth) are selected in our experiments. As a result, our proposal successfully ensures the appropriate quality of service and quality of experience to the end users when the service of stereoscopic IPTV is being delivered.  相似文献   

10.
SONET/SDH technologies constitute the core transport infrastructure of major telecom service providers worldwide. As the percentage of packet-oriented traffic in the overall traffic demand continues to rise, prompted by the widespread adoption of the Internet protocol suite, and recently by the fast adoption of Ethernet services, there is increasing pressure to improve the service provider's transport infrastructure in ways that make it data-aware and cost-effective for packet-oriented applications. Steps in this direction include the adoption of native physical interfaces, for Ethernet and storage area networks as service interfaces, or full integration of packet switching capabilities from Ethernet, resilient packet ring, and MPLS technologies. This article discusses the emerging building blocks for next-generation data-aware transport networks and next-generation transport network elements.  相似文献   

11.
Optimized routing for providing ethernet LAN services   总被引:1,自引:0,他引:1  
Ethernet's-move into metropolitan and wide area networks is driving a rapidly growing market opportunity. Current Ethernet services come in two basic flavors, Ethernet line and LAN, providing point-to-point and multipoint connectivity, respectively. The LAN services, although more cost effective, are lagging behind in deployments due to associated QoS and bandwidth provisioning issues. The Ethernet service provider needs to provision the network to meet current and future traffic demands, where the traffic is unpredictable and bursty. The goal is to minimize. overprovisioning and complexity. To add to the challenge, Ethernet routing is based on simple self-learning and relies on spanning tree routing. In this article we propose an Ethernet-specific load balanced routing mechanism, which is robust to dynamic traffic demand. It significantly reduces overprovisioning, is simple and static, and requires only bandwidth profiles associated with service level agreements at the ingress and egress links. Our simulation results show that our scheme provides performance improvements over a recently proposed approach for switched Ethernet as well as a related load balancing approach for Ethernet over MPLS networks.  相似文献   

12.
The arrival of cloud computing technology promises innovative solutions to the problems inherent in existing vehicular ad hoc network (VANET) networks. Because of the highly dynamic nature of these networks in crowded conditions, some network performance improvements are needed to anticipate and disseminate reliable traffic information. Although several approaches have been proposed for the dissemination of data in the vehicular clouds, these approaches rely on the dissemination of data from conventional clouds to vehicles, or vice versa. However, anticipating and delivering data, in a proactive way, based on query message or an event driven has not been defined so far by these approaches. Therefore, in this paper, a VANET‐Cloud layer is proposed for traffic management and network performance improvements during congested conditions. For the traffic management, the proposed layer integrates the benefits of the connected sensor network (CSN) to collect traffic data and the cloud infrastructure to provide on‐demand and automatic cloud services. In this work, traffic services use a data exchange mechanism to propagate the predicted data using a fuzzy aggregation technique. In the evaluation phase, simulation results demonstrate the effectiveness of the proposed VANET‐Cloud layer to dramatically improve traffic safety and network performance as compared with recent works.  相似文献   

13.
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.  相似文献   

14.
业务的多样性和不断出现的新业务正在驱动网络的发展,以IPTV为代表的基于流媒体的业务对光网络提出了新的挑战,光网络需要引入组播功能,支持组播业务。组播功能的引入使得光网络的带宽利用率得到有效提高。组播是未来光网络必不可少的技术。层叠网络的进一步演进,将进一步融合IP组播和光网络组播。未来,可以通过降低光网络组播树的粒度来降低光组播的使用门槛,这将有利于促进组播技术的更广泛使用。  相似文献   

15.
目前的网络多媒体业务越来越强调交互,强调用户参与,而多屏业务(手机屏,电脑屏,IPTV电视屏)由于跨越3种异构网络(移动通信网、有线以太网、广电网/电信IPTV网),涉及3种终端,交互在多屏业务中的作用就更加突出了。因此,我们必须给出一套跨越3种异构网络进行交互的方案,能够使用户尽情享受眩彩多屏业务。OMA国际标准中已经规定了交互机制以及异构网络下的设备管理机制,本文就利用OMA国际标准中的交互机制以及设备管理机制构建了一套智能交互式多屏解决方案。  相似文献   

16.
17.
Internet protocol television (IPTV) service depends on the network quality of service (QoS) and bandwidth of the broadband service provider. IEEE 802.16j mobile multihop relay Worldwide Interoperability for Microwave Access networks have the opportunity to offer high bandwidth capacity by introducing relay stations. However, to actually satisfy QoS requirements for offering IPTV services (HDTV, SDTV, Web TV, and mobile TV) for heterogeneous users' requests, providers must use a video server for each IPTV service type, which increases the network load, especially bandwidth consumption and forwarding time. In this paper, we present a solution for forwarding IPTV video streaming to diverse subscribers via an 802.16j broadband wireless access network. In particular, we propose a new multicast tree construction and aggregation mechanism based on the unique property of prime numbers. Performance evaluation results show that the proposed scheme reduces both bandwidth consumption and forwarding time.  相似文献   

18.
We experimentally demonstrate error free performance of a simple ring-based Ethernet Passive Optical Network (EPON) architecture that supports truly shared LAN capability among users as well as a fully distributed dynamic bandwidth allocation DBA scheme. The proposed distributed architecture can also be utilized as a packet-based mobile backhaul transport network to backhaul emerging mobile services across the PON-based fiber infrastructure. Utilizing PON access infrastructure as a mobile backhaul enables a seamless migration path to fixed-mobile convergence solutions.  相似文献   

19.
The evolution of transport network survivability   总被引:12,自引:0,他引:12  
The bandwidth explosion ushered in by the popularity of the Internet has spurred the acceleration in the development and deployment of equipment supporting packet-based services. This-coupled with the widespread deployment of dense wavelength-division multiplexed systems in the core transport network to satisfy the corresponding increase in capacity demand-has led network planners to reconsider traditional approaches to network survivability. Existing architectures for transport network survivability were developed based on a ubiquitous circuit-switched/TDM network paradigm. As tariffed services increasingly migrate from circuit-switched/TDM to packet-switched/DWDM networks, survivability architectures must also evolve to meet the service requirements of this “new” packet-switched/DWDM network paradigm. We begin with an overview of existing strategies for providing transport network survivability, followed by an analysis of how the architectures for network survivability may evolve to satisfy the requirements of emerging networks  相似文献   

20.
Carrier-grade Ethernet challenges for IPTV deployment   总被引:1,自引:0,他引:1  
Carrier-grade Ethernet standardization and deployment is gaining momentum due to the ease of deployment, lower cost, and compatibility with existing networks on the access end. When Internet protocol television (IPTV) is deployed using Ethernet as the underlying interconnect fabric infrastructure, meeting fine-grained traffic management (TM) requirements on the service provider side to meet quality of service (QoS), billing, and security features implementation on the user side poses several challenges. Such challenges could be met using the TM features built into network processors (NPs).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号