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介绍了IP电话网守的概念,功能和呼叫信令的两种方式,讨论了呼叫转移在IP电话中的一种实现方法,在局域网、单网守的条件下得到了实现。 相似文献
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The low-cost of packet-based networking technologies with respect to traditional circuit-switched ones and the reliability of the current (wired) IP networks have brought to a considerable employment of the VoIP (Voice over IP) technologies in the voice services market. This success is expected to happen also in mobile ad hoc networks (MANETs), which may offer a good platform for the fast deployment of VoIP mobile networks. However, efforts must be made to improve performance before MANETs can be used for this purpose. One of the main limitations is related to the highly variability of the network topology and channel behavior, which heavily influences the service quality due to route losses and significant delay variations. In this paper, we propose a strategy where these impairments are jointly addressed. The source is responsible for jointly selecting the transmission paths and adjusting the playout delay, with an adaptive inter-talkspurt approach. These tasks are accomplished on the basis of historical data on network connectivity and transmission delays, and are driven by a quality-based approach. The collection of statistics of the network status relies on the QOLSR routing algorithm, whereas the voice quality is measured by means of the ITU-T E-Model. 相似文献
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文章分析了将UM业务融入IP电话系统中实现的优越性 ,确定了通过IP电话系统网守实现对UM服务器的管理机制 ,研究了该UM服务器的主要技术、系统结构、媒体信息的收发方式和安全策略等关键问题 ,完成了基于IP电话系统的UM业务的实现方案并成功开发了这一方案的UM原型系统。 相似文献