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1.
最近,一个名不见经传的公司开始了与几个地方贝尔经营公司(RBOC)的竞争。美国WEST公司是地方贝尔经营公司(RBOC)的一个成员,它的数据传送与网络集成部门,Interprise连网业务分部,正在美国西部地区之外的几个市场开拓业务。 Interprise分部将通过竞争接入提供者(CAP)专用接入线与RBOC直接竞争帧中继和增值数据业务。Interprise分部已向美国WEST公司经营范围的几百家公司和政府机关提供数据业务和网络集成。  相似文献   

2.
随着电信业的放开被提上华盛顿的立法日程,各地方贝尔运营公司(RBOC)正促进信息业的自由竞争。一旦法律允许,长途电信业与RBOC正准备互相侵入对方的地盘,但是,一个第三集团,也在准备赚电信的钱,这就是地方及区域有线电视运营商。 有线电视运营商处于一个独特的位置,可以利用电信业  相似文献   

3.
美国贝尔大西洋公司和通用电话电子公司近日宣布合并。合并金额达529亿美元的新公司,其规模仅次于AT&T,总部将设在纽约。贝尔大西洋是1984年分割的7个小贝尔之一,在美国东部区经营地方电话业务,而通用电话电子公司在美国41个州独立经营地方电话和长话业务。美国两大电话公司合并  相似文献   

4.
《电信网技术》2004,(9):48-48
近日,爱立信与MCI公司双方就部署爱立信Engine下一代多业务网络解决方案达成了协议,该协议旨在把MCI位于美国的国际网关业务从传统的电路交换演进至电信级VoIP软交换。在美国推出爱立信的Engine下一代多业务网络解决方案是MCI融合网络战略的关键举措。这种电信级、标准化的VoIP软交换解决方案将使MCI能够通过其IP骨干网在全球传输语音流量,同时还可以扩展网络功能,并在全球范围内提供下一代多媒体业务。  相似文献   

5.
在本地交换电话市场的竞争中,运营公司各有新招,不甘落伍。尽管MCI的一家子公司MCI Metro有限公司的总经理否认竞争的存在。(该公司负责地方Bell运营公司(RBOC)在国内最大城市的业务)。  相似文献   

6.
关于人们是否真正需要窄带异步传输模式(ATM)的争论已经结束,除几个顽固者外,其他厂商和通信公司都愿把宝压在T1 ATM上。 因其价位比帧中继更具竞争力,用户和厂商均看好这项业务。到1996年底,美国大部分地区都可使用T-1 ATM业务。 在地方贝尔经营公司中,Ameritech公司、贝尔大西洋公司和SBC通信公司都已独立提供T-1 ATM业务。贝尔南方  相似文献   

7.
美国两家最大的有线电视经营厂商——Time warner公司和Telecommunications Inc.公司(TCI)同Sprint公司一起把它们的目标对准了地区贝尔经营公司(RBOC)的基本用户——商业用户。与此同时,三家RBOC——Bell Atlantic,NYNEX和Pacific Telesis——共同集资3亿美元的现金,准备把娱乐影视节目直接送到居民住宅。 Time warner和TCI在策略和措施上展开竞争。Time warner在规模上仅次于TCI,它把目标集中在人口密集的地区如纽约,在那里它能方便而经济地提供电话服务。与此同时,TCI正在研制一个适合于大地域的模式,其中包括在有线  相似文献   

8.
最终用户对成熟技术的需求、激烈的市场竞争带来的增加ARPU值和降低成本的压力,使许多电信运营商(包括传统话音业务运营商)加快了部署VoIP业务的步伐。VoIP的话务量已经从1998年的1.5亿分钟增加到2002年的150亿分钟。目前,全球75%的服务提供商已经部署或正计划部署VoIP。业界对高质量的VoIP表现出极为浓厚的兴趣,而传统的VoIP还存在着不少问题,无法满足市场需求。Juniper以J-Voice的品牌向市场提供一整套技术,该技术不仅仅使分组话音业务得以实现,而且还确保用户能享受高质量的分组话音体验。目前尚无其他厂商或技术可以提供同等水…  相似文献   

9.
已经证明,1995年是多频道电视业多事之秋的一年——直播卫星(DBS)的卓越成功、传送数字视频的廉价设备快速研制、美国区域贝尔经营公司(RBOC)进入无线电缆领域、以及激励美国多频道电视供应商之间开展竞争的政策法规的实施,所有这些均意味着,电缆电视业将面临着来自 DBS 和无线电缆电视的更激烈的竞争。国际无线电缆协会(WCA)副主席安德鲁·克雷格(Andvew Kreig)说,一次新的  相似文献   

10.
乔楠 《通信世界》2005,(11):54-54
近日,南方贝尔和Qwest通信公司提出了关于应如何从VoIP市场中获取利润从而实现最佳定位的两种战略模型。目前VoIP还存在很多问题。而南方贝尔认为,当VoIP问题逐渐趋于明朗,电信运营商将拥有更大的网络灵活性。事实上,南方贝尔现在已经掌握了在原有接入网上加载VoIP流量的技术,同时确保有效组织和管理端到端IP格式的流量。  相似文献   

11.
12.
Most major carriers are deploying multiprotocol label switching (MPLS) and are also migrating voice traffic to packet transport. This article analyzes how those trends can be combined. It compares the advantages of VoMPLS with VoATM, VoIP, and VoFR, from the viewpoints of bandwidth utilization, implementation issues, and the region of the network (access/backbone) in which implementation takes place. VoMPLSoPPP is more efficient than VoMPLSoATM or VoMPLSoEthernet. In the network backbone VoMPLSoPPP is most efficient. VoAAAL2oATM has intermediate efficiency, and VoIP is highly inefficient. In the access network use of header compression improves the efficiency of VoIP but does not bring it to the level of VoAAL2oATM, which is approximately as efficient as VoMPLSoEthernet. VoMPLSoPPP remains most efficient.  相似文献   

13.
In a wireless multi-hop network environment, energy consumption of mobile nodes is an important factor for the performance evaluation of network life-time. In Voice over IP (VoIP) service, the redundant data size of a VoIP packet such as TCP/IP headers is much larger than the voice data size of a VoIP packet. Such an inefficient structure of VoIP packet causes heavy energy waste in mobile nodes. In order to alleviate the effect of VoIP packet transmission on energy consumption, a packet aggregation algorithm that transmits one large VoIP packet by combining multiple small VoIP packets has been studied. However, when excessively many VoIP packets are combined, it may cause deterioration of the QoS of VoIP service, especially for end-to-end delay. In this paper, we analyze the effect of the packet aggregation algorithm on both VoIP service quality and the energy consumption of mobile nodes in a wireless multi-hop environment. We build the cost function that describes the degree of trade-off between the QoS of VoIP services and the energy consumption of a mobile node. By using this cost function, we get the optimum number of VoIP packets to be combined in the packet aggregation scheme under various wireless channel conditions. We expect this study to contribute to providing guidance on balancing the QoS of VoIP service and energy consumption of a mobile node when the packet aggregation algorithm is applied to VoIP service in a wireless multi-hop networks.  相似文献   

14.
Service overlay networks: SLAs, QoS, and bandwidth provisioning   总被引:3,自引:0,他引:3  
We advocate the notion of service overlay network (SON) as an effective means to address some of the issues, in particular, end-to-end quality of service (QoS), plaguing the current Internet, and to facilitate the creation and deployment of value-added Internet services such as VoIP, Video-on-Demand, and other emerging QoS-sensitive services. The SON purchases bandwidth with certain QoS guarantees from the individual network domains via bilateral service level agreement (SLA) to build a logical end-to-end service delivery infrastructure on top of the existing data transport networks. Via a service contract, users directly pay the SON for using the value-added services provided by the SON. In this paper, we study the bandwidth provisioning problem for a SON which buys bandwidth from the underlying network domains to provide end-to-end value-added QoS sensitive services such as VoIP and Video-on-Demand. A key problem in the SON deployment is the problem of bandwidth provisioning, which is critical to cost recovery in deploying and operating the value-added services over the SON. The paper is devoted to the study of this problem. We formulate the bandwidth provisioning problem mathematically, taking various factors such as SLA, service QoS, traffic demand distributions, and bandwidth costs. Analytical models and approximate solutions are developed for both static and dynamic bandwidth provisioning. Numerical studies are also performed to illustrate the properties of the proposed solutions and demonstrate the effect of traffic demand distributions and bandwidth costs on SON bandwidth provisioning.  相似文献   

15.
The traditional telecommunications operator of China has entered into a substantive network construction stage of NGN and new VoIP service in 2006. As the increasing understanding and the consideration of cost to VoIP, VoIP has become more acceptable for CIO of large-scale enterprises. Small and medium-scale enterprises are sensitive to communication cost, but influenced by the maturity of VoIP technology and reduction of VoIP equipment price, the market is intensified. All these drive the VoIP equipment entering into the actual purchase stage and promote the stable growth of VoIP equipment scale.  相似文献   

16.
关于NGN若干问题的思考--从VoIP到NGN   总被引:1,自引:1,他引:0  
李晓明 《电信科学》2005,21(4):30-33
本文在综述了VoIP的三个发展阶段之后,分别提出了NGN业务网的十大问题、分组业务网的完备性、NGN业务网的评价体系,最后对目前已出现的分组业务网技术体系进行了评价.  相似文献   

17.
简单介绍基于HFC网络的电路交换语音解决方案,着重论述基于HFC网络和DOCSIS系统的VoIP解决方案,根据SCN的VoIP试验情况,提出有线运营商部署VoIP业务平台时的难点和应该考虑的问题,最后指出有线运营商应该充分利用其网络资源,积极进行语音业务的拓展,推出有竞争力的语音产品,满足用户的需求。  相似文献   

18.
In this letter we show a fault localization system implemented by using policy-based thresholds for triggering alarms or self-healing mechanisms. Alarms are collected and organized within a codebook, which is a fundamental component of our fault management system. The relevant performance is analyzed by using a real network deploying VoIP services.  相似文献   

19.
Performance Optimizations for Deploying VoIP Services in Mesh Networks   总被引:1,自引:0,他引:1  
In the recent past, there has been a tremendous increase in the popularity of VoIP services as a result of huge growth in broadband access. The same voice-over-Internet protocol (VoIP) service poses new challenges when deployed over a wireless mesh network, while enabling users to make voice calls using WiFi phones. Packet losses and delay due to interference in a multiple-hop mesh network with limited capacity can significantly degrade the end-to-end VoIP call quality. In this work, we discuss the basic requirements for efficient deployment of VoIP services over a mesh network. We present and evaluate practical optimizing techniques that can enhance the network capacity, maintain the VoIP quality and handle user mobility efficiently. Extensive experiments conducted on a real testbed and ns-2 provide insights into the performance issues and demonstrate the level of improvement that can be obtained by the proposed techniques. Specifically, we find that packet aggregation along with header compression can increase the number of supported VoIP calls in a multihop network by 2-3 times. The proposed fast path switching is highly effective in maintaining the VoIP quality. Our fast handoff scheme achieves almost negligible disruption during calls to roaming clients  相似文献   

20.
介绍了VoIP网络电话特点和应用现状,研究了Trixbox开源软件的结构、组成特点。设计了网络电话的系统结构,从服务器系统配置出发,重点讨论了VoIP网络电话系统图形化配置方案。针对IP网络电话安全问题提出了若干解决方案,对于搭建中小企业网络电话服务平台具有借鉴意义。  相似文献   

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