【作者】 俞一丹；

【导师】 黄旭； 孙鉴军；

【作者基本信息】 苏州大学 ， 电子与通信工程， 2007， 硕士

【摘要】 软交换是一个基于软件的分布式的交换/控制平台。这种网络可将呼叫控制功能从网关中分离出来,能开放业务、控制、接入和交换之间的协议,从而真正实现多厂家运营的环境,使网络业务的引入更加方便。软交换技术已经成为下一代网络的核心技术。软交换网络是基于IP技术的网络,语音业务则是软交换网络中最基本的业务之一。由于目前软交换网络尚处于试验阶段,其业务并未完全商用,为了使基于软交换的语音业务达到电信级服务质量,需要对软交换业务的QoS保证进行研究。由于IP网络性能对其承载的业务有着直接的影响,因此针对软交换的承载网络——IP网络进行网络性能方面的研究变得尤为关键。本文通过对软交换网络、业务模式、承载网的组网及其性能测评方案的研究,针对苏州电信软交换试验网的承载网络进行了一次全面的性能测试和评估。确定了一套基于IP网络的软交换语音业务的性能测评方案:根据苏州电信软交换试验网的结构设置6个测试点,通过主动式定量的测试方式,在测试点之间产生真实的应用层流量,测试待测网络在实际应用中端到端的性能。测试时选用美国IXIA公司的IxChariot测试软件进行测试,通过对MOS值、延时、抖动和丢包四个指标的输出数据进行统计分析,对该承载网的性能进行测评。测试结果表明,NGN承载网承载语音业务的性能总体状况良好,但在个别网络路径上存在间隙性的连续丢包现象,且连续丢包时间最长达到10秒,使该路径有超过0.5%的语音会话质量偏差,反映出以IP方式承载的软交换网络在服务质量方面存在的问题。最后根据评估结果给出了一些优化建议,以通过对承载网性能的改善,实现对软交换服务质量的改进。更多还原

【Abstract】 Softswitch theory is a kind of distributed switching and controlling platform based on software. The calling service is separated from the gateway in this kind of network, so that an environment with multi-suppliers is coming true via opening the protocols between the business, control, insert and exchange, and it is much more convenient to bring new network service. The softswitch technology is the hardcore in the next generation of network.Softswitch network derived from the IP network, so the voice service is one of the most basic businesses in the softswitch net. Since the present softswitch is still in pilot-run, it is necessary to research in the QoS of the softswitch in order to raise the quality of the voice service in the softswitch network. It is really necessary to research on the performance of the IP net witch is not only the carrier network of the softswich net, but also affect the services in the softswitch net.This paper tests and evaluates the carrier network of Suzhou Telecom via researching the softswitch network, business mode, buildup of the carrier network and performance. A testing method is provided. In this method, 6 testing stations are set up in the testing carrier network of Suzhou Telecom, in order to calculate the real P2P data quantity in the application layer. In this paper, we used testing software named IxChariot, which is provided by IXIA. The carrier network is evaluated by testing MOS, one-waydelay, jitter and lost data. In this test, we find the performance of the voice service in the NGN carrier network is good. However some problems are found, such as the consecutive lost-datagrams would last about 10 second some time in some channel, and 0.3% of the quality of the voice service is down. So we can find there are some problems on the QoS in the IP net, witch is also the carrier network of softswitch network. Some advice is offered to improve the network based on this testing method and the final purpose is to push the QoS of the softswitch via optimizing the performance of the carrier network.更多还原