当前位置:考试网  > 试卷库  > 计算机类  > 软考  > 中级软考  > 网络工程师  >  信息高速公路的建设促进了电信产业的结构调整,出现了大规模的企业重组和业务转移, 电信运营商纷纷把竞争的重点和大量的资金,从广域网的建设,转移到高效、经济、支持大 量用户接入和持多种业务的城域网的建设之中。回答问题 1 到问题 3。 【问题 1】宽带城域网的网络平台采用什么样的结构,这种结构有何优越性。 【问题 2】组建城域网的基本原则是什么? 【问题 2】组建城域网的基本原则是什么?
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信息高速公路的建设促进了电信产业的结构调整,出现了大规模的企业重组和业务转移, 电信运营商纷纷把竞争的重点和大量的资金,从广域网的建设,转移到高效、经济、支持大 量用户接入和持多种业务的城域网的建设之中。回答问题 1 到问题 3。

【问题 1】宽带城域网的网络平台采用什么样的结构,这种结构有何优越性。

【问题 2】组建城域网的基本原则是什么?

【问题 2】组建城域网的基本原则是什么?

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正确答案:

问题一

宽带城域网网络平台采用层次结构。采用层次结构的优点是:结构清晰,各层功能实体之 间的定位清楚,接口开放,标准规范,便与组建和管理。

从逻辑上,网络平台结构可以分为:核心交换层、边缘汇聚层与用户接入层。核心层连接 多个汇聚层与主干网络,主要承担高速数据交换的能力,提供城市的带宽 IP 数据出口;汇聚 层主要承担路由与流量汇聚的功能;接入层重点解决的是“最后一公里”的问题,主要承担 用户接入本地流量控制的功能。实际应用中,根据当前数据交换量、接入的用户数量与业务 类型等因素的要求,确定宽带城域网的结构与层次。

问题二

与广域网、局域网相比,城域网的结构、服务更为复杂,其制约的关键在于各类接点的带 宽管理与业务调度能力。要组建与成功运营一个宽带城域网要遵循的基本原则是:必须能够 保证网络的可运营性、可管理性、可盈利性和可扩展性。

(1)可运营性:组建的网络一定是可运营的,必须能够保证系统提供 7 24 小时的服务, 并却保证服务质量。 首先要解决技术选择与设备选型问题, 其核心与关键设备一定是电信级’ 的。

(2)可管理性:必须要有足够的网络管理能力。表现在电信级的接入管理、业务管理、网 络安全、计费能力、 IP 地址分配、 QoS保证等方面。

(3)可盈利性: 可盈利性要求组建宽带城域网必须定位在可以开展的业务上; 要求能够区 分高价值用户和普通用户,培育和构建合理的宽带价值链。

(4)可扩展性:即组网的灵活性、对新业务与网络规模、用户规模扩展的适应性。这是由 网络技术发展的不确定及网络需求的变化决定的。

问题三

城域网发展的主要业务有: 高速上网业务、 网络互联业务、 电子政务与电子商务业务服务、 智能社区服务、网上教育与远程医疗服务、带宽与管道出租服务等。

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