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SIP协议在一个IP电话模型中的实现 总被引:4,自引:1,他引:4
提供优质的IP会话是未来多媒体通信业务的关键问题。会话初始协议(SIP)是多媒体数据和控制体系的一部分,是一个基于应用层的控制协议。文中提出了一种在现有电话通信系统的基础上,不需要建立新的体系结构,经简单改造即可实现的新型IP电话系统的构想。该新型IP电话系统可以实现更廉价和便捷的IP通话。文中阐述了设计和实现方案,给出了该IP电话系统的网络框架,讨论了SIP的工作原理和在该系统中的实现。 相似文献
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提供优质的IP会话是未来多媒体通信业务的关键问题.会话初始协议(SIP)是多媒体数据和控制体系的一部分, 是一个基于应用层的控制协议.文中提出了一种在现有电话通信系统的基础上,不需要建立新的体系结构,经简单改造即可实现的新型IP电话系统的构想.该新型IP电话系统可以实现更廉价和便捷的IP通话.文中阐述了设计和实现方案,给出了该IP电话系统的网络框架,讨论了SIP的工作原理和在该系统中的实现. 相似文献
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SIP代理服务器的设计与实现 总被引:2,自引:1,他引:2
SIP(Session Initiation Protocol,会话初始化协议)是一个应用层信令控制协议,用来创建、修改和终结一个或多个参与者参加的会话,这些会话包括IP电话、分布式多媒体、多媒体会议等。本文基于SIP协议,提出了一个SIP 代理服务器的设计与实现方案。 相似文献
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基于SIP的集中式多媒体会议系统的研究 总被引:5,自引:0,他引:5
基于IP网络的多媒体会议系统是一个重要的研究课题。该文通过对各种会议拓扑结构的分析和比较,提出了一种以SIP作为控制信令的、集中式拓扑结构的多媒体会议系统。在给出了系统的框架结构之后,该文研究了如何扩展基本的SIP协议来完成会议控制的功能,并针对几种常用的会议控制功能,给出了详细的控制机制。 相似文献
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郑志军 《计算机光盘软件与应用》2011,(9)
IMS是3GPP在Release5版本中提出的支持IP多媒体业务的子系统,SIP是一种应用层控制协议,用于生成、修改和终止一人或者多人的多媒体会话,SIP是IMS的基本控制协议.本文首先简要介绍IMS和SIP协议,然后介绍SIP协议在IMS中的基本应用和扩展应用. 相似文献
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《Information Security Journal: A Global Perspective》2013,22(2):16-21
Abstract The deployment of Voice-over-IP (VoIP), or IP telephony, is accelerating rapidly. Due to the numerous benefits of VoIP systems, including the reduced cost of deployment and management, IP-PBXs are now outselling traditional PBXs and, by 2009, will represent 91 percent of all enterprise phone systems worldwide. As more and more private- and public-sector organizations and service providers plan the migration to VoIP and the associated emerging real-time services, such as IP TV, conferencing, and IP multimedia subsystem (IMS), the need to secure IP communications is becoming increasingly urgent. 相似文献
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Kevin Doolin Robert Mullins Rafael Morón Abad Marta García Moreno Telma Mota Babak A. Farshchian Miguel Gómez 《Journal of Network and Systems Management》2008,16(1):92-112
Natural communication among people happens in flexible ways and is strongly affected by the users’ situation (such as communication
tools available, user’s location, and user’s preferences). This situation or context information is seldom used to initiate
communication sessions among users. Current communication systems are indifferent about users’ context, often require time
consuming manual configurations and often result in conferencing tools not being easily accessible when needed. This leads
to lower adoption of innovative communications services. IMS SIP (IP Multimedia Subsystem, Session Initiation Protocol) sessions
allow users to access the session from different points of contact (home, office, etc.), however, IMS still requires a prior
knowledge of all SIP components that might be used in a SIP session. Furthermore, IMS makes limited use of context information
(mainly user-defined availability). To address these issues our research approach combines techniques from pervasive computing
with IMS networking principles to facilitate compositions of communication sessions based on users’ context. We propose a
platform and APIs for pervasive application development support to allow greater intelligence in IMS applications. We additionally
provide mechanisms for IMS applications to apply their intelligence to the configuration of physical devices and web resources
used to set up a conference. The innovations proposed in this paper are: (1) A new standard for intelligent IMS-based conferencing
applications. (2) Application Development Interfaces (APIs) for a platform for pervasive computing. (3) An architecture for
a pervasive IMS platform.
相似文献
Kevin DoolinEmail: |
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The IP Multimedia Subsystem (IMS) is defined by the 3
rd
Generation Partnership Project (3GPP) as a new core network domain. IMS provides a service control platform that allows creation
of new multimedia and multi-session applications utilizing wireless and wireline transport capabilities. In this paper we
will cover the concepts and standards defining IMS and review the network architecture from a mobile perspective. We will
see how IMS interacts with the Packet Switched Domain (e.g. Wireless LAN, GPRS, and UMTS networks), the Internet, and application
services. Then we will examine the key IMS capabilities and show how they can be combined to create new mobile IP services.
Finally, we present a software architecture, which is enabled by IMS and allows development of unique applications (with multimedia/multi-session
functionality, single/multi-user, service to user). The software architecture is illustrated by an example of a prototype
application.
This work was done when the author was with Siemens Communications Inc., Boca Raton, FL 相似文献
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The IP Multimedia Subsystem (IMS) is defined by the 3rd Generation Partnership Project (3GPP) as a new core network domain. IMS provides a service control platform that allows creation
of new multimedia and multi-session applications utilizing wireless and wireline transport capabilities. In this paper we
will cover the concepts and standards defining IMS and review the network architecture from a mobile perspective. We will
see how IMS interacts with the Packet Switched Domain (e.g. Wireless LAN, GPRS, and UMTS networks), the Internet, and application
services. Then we will examine the key IMS capabilities and show how they can be combined to create new mobile IP services.
Finally, we present a software architecture, which is enabled by IMS and allows development of unique applications (with multimedia/multi-session
functionality, single/multi-user, service to user). The software architecture is illustrated by an example of a prototype
application.
This work was done when the author was with Siemens Communications Inc., Boca Raton, FL 相似文献
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Three studies of collaborative activity were conducted as part of research in developing multimedia technology to support collaboration. One study surveyed users' opinions of their use of video conference rooms. Users indicated that the availability of the video conference rooms was too limited, audio quality needed improvement, and a shared drawing space was needed. A second study analyzed videotapes of a work group when meeting face-to-face, video conferencing, and phone conferencing. The analyses found that the noticeable audio delay in video conferencing made it difficult for the participants to manage turn-taking and coordinate eye glances. In the third study, a distributed team was observed under three conditions: using their existing collaboration tools, adding a desktop conferencing prototype (audio, video, and shared drawing tool), and subtracting the video capability from the prototype. Qualitative and quantitative data were collected by videotaping the team, interviewing the team members individually, and recording their usage of the phone, electronic mail, face-to-face meetings, and desktop conferencing. The team's use of the desktop conferencing prototype dropped significantly when the video capability was removed. Analysis of the videotape data showed how the video channel was used to help mediate their interaction and convey visual information. Desktop conferencing apparently reduced e-mail usage and was perceived to reduce the number of shorter, two-person, face-to-face meetings. 相似文献
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一个桌式数据会议系统的原型:多媒体技术的一个新应用 总被引:2,自引:2,他引:0
本文介绍一个自行设计和开发的桌式数据会议系统。该会议系统实现于UNIX工作站和TCP/IP网络上,并充分利用了多媒体技术,文中指出了桌式数据会议系统的基本要求和其实现中的技术关键。 相似文献
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This paper analyzes the session setup delay in the IP multimedia subsystem (IMS) with the CDMA2000 evolution data only rev. A (EV-DO rev. A) standard for wireless transmission. Session setup delay is particularly critical for interactive multimedia applications, such as gaming, push-to-X and voice over IP (VoIP), as it directly translates in user perception of service quality. Keeping signaling delay low, however, is a challenge in IMS due to the text-based nature of the session initiation protocol (SIP) for signaling, and, more significantly, due to the lossy and capacity constrained wireless links. To address this challenge, we analyze the session setup delay end-to-end, by taking into account key system properties across all layers, ranging from radio links to IMS signaling architecture. We present a model for cross-layer performance analysis and simulation, which includes the statistical properties of the EV-DO (rev. A) wireless channel, and also takes into consideration the properties of transport protocols (TCP, UDP) and SIP signaling (message size and compression). By means of analysis and simulations, we study the setup delay performance of a generic, multi-operator IMS communication scenario between two mobile users. We describe how session setup delay can be estimated and reduced in realistic IMS settings and we propose architecture alternatives to the basic IMS scenario. The results derived from this study show that the proposed methods can incrementally lead to a lower setup delay and less sensitivity to the radio transmission quality and frame error rate compared to the base IMS scenario 相似文献