支持IP组播的多媒体会议系统关键技术研究
摘要
多媒体会议是目前相对较新的通信应用领域。随着视频会议应用的推广，IP组播网络技术也得到了迅速的发展。本文对支持IP组播的多媒体会议系统设计中的一些关键技术做了深入研究与分析。
本文首先提出了支持IP组播的多媒体会议系统的研究目标与背景，简单介绍了多媒体通信的发展与应用，介绍了多媒体会议的重要技术基础——IP组播与多媒体通信协议的发展，并且讨论了多媒体会议系统的特点。
接着，本文介绍了基于分组的多媒体通信系统——H.323系统的体系结构，以及IP组播的基本概念及机制。
针对本文提出的支持IP组播的多媒体会议系统，介绍了其组成端点的体系结构，重点描述了其中的关键成分。
本文对IP组播应用于多媒体会议中的一些关键技术做了深入研究，包括IP组播的实现方案、音频与视频的实时传输、会议公告，并对IP组播应用的优点与不足进行了分析与讨论。
本文描述了多媒体会议系统的支持组播多点通信模式的会议实现。
最后，本文进行了总结，并对多媒体会议的研究与应用做出展望。
The multimedia conference is a developing application of telecommunication. On the other hand, with videoconference applications' extending. IP multicast networks makes fast progress. This article comes up with the multimedia conference system supporting IP multicast, and researches and analyses some involved key technologies.
First, this article brings forward the objective of research on the multimedia conference system supporting IP multicast, and the background of it, introduces the development and applications of multimedia communications, the important basic technologies of the multimedia conference, and the features of the multimedia conference.
Then, the article introduces the architecture of the multimedia communication system
over the packet-based networks------H.323 system, and the key conceptions and
principles of the IP multicast.
This article summarizes the multimedia conference system supporting IP multicast, introduces the architecture of the component endpoint, and describes some involved key elements.
The article researches and analyses some key technologies used to apply IP multicast to multimedia conference systems, including the implementation schemes of the IP multicast, real-time transportation of audio and video, conference announcement, and analyses and discusses the application of the IP multicast.
The article describes the implementation of multimedia conferences supporting multipoint modes using IP multicast.
In the end, this article presents a summary and gives a prospect to the future research on the multimedia conference applications.
本文首先提出了支持IP组播的多媒体会议系统的研究目标与背景，简单介绍了多媒体通信的发展与应用，介绍了多媒体会议的重要技术基础——IP组播与多媒体通信协议的发展，并且讨论了多媒体会议系统的特点。
接着，本文介绍了基于分组的多媒体通信系统——H.323系统的体系结构，以及IP组播的基本概念及机制。
针对本文提出的支持IP组播的多媒体会议系统，介绍了其组成端点的体系结构，重点描述了其中的关键成分。
本文对IP组播应用于多媒体会议中的一些关键技术做了深入研究，包括IP组播的实现方案、音频与视频的实时传输、会议公告，并对IP组播应用的优点与不足进行了分析与讨论。
本文描述了多媒体会议系统的支持组播多点通信模式的会议实现。
最后，本文进行了总结，并对多媒体会议的研究与应用做出展望。
The multimedia conference is a developing application of telecommunication. On the other hand, with videoconference applications' extending. IP multicast networks makes fast progress. This article comes up with the multimedia conference system supporting IP multicast, and researches and analyses some involved key technologies.
First, this article brings forward the objective of research on the multimedia conference system supporting IP multicast, and the background of it, introduces the development and applications of multimedia communications, the important basic technologies of the multimedia conference, and the features of the multimedia conference.
Then, the article introduces the architecture of the multimedia communication system
over the packet-based networks------H.323 system, and the key conceptions and
principles of the IP multicast.
This article summarizes the multimedia conference system supporting IP multicast, introduces the architecture of the component endpoint, and describes some involved key elements.
The article researches and analyses some key technologies used to apply IP multicast to multimedia conference systems, including the implementation schemes of the IP multicast, real-time transportation of audio and video, conference announcement, and analyses and discusses the application of the IP multicast.
The article describes the implementation of multimedia conferences supporting multipoint modes using IP multicast.
In the end, this article presents a summary and gives a prospect to the future research on the multimedia conference applications.
引文
[1] Steve Deering, RFC 1112: Host Extension for IP Multicast, 1998.8
[2] ITU-T Recommendation H.323 v4, Packet-based multimedia communications systems, 2000.11
[3] ITU-T Recommendation H.225.0, Call signalling protocols and media stream packetization for packet based multimedia communication systems, 1999
[4] ITU-T Recommendation H.245, Control protocols for multimedia communication, 2000
[5] ITU-T Recommendation T.120, Data protocols for multimedia conferencing, 1996
[6] ITU-T Recommendation Q.931, ISDN user-network interface layer 3 specification for basic call control, 1998
[7] Trillium Digital Systems, Inc., H. 323 Tutorial
[8] ITU-T Recommendation H.246, Interworking of H-Series multimedia terminals with H-Series multimedia terminals and voice/voiceband terminals on GSTN and ISDN, 1998.2
[9] H. Schulzrinne, S. Casner, R. Frederick, V. Jacobson, RFC 1889: RTP: A Transport Protocol for Real-Time Applications, 1996.1
[10] H. Schulzrinne, RFC 1890: RTP Profile for Audio and Video Conferences with Minimal Control, 1996.1
[11] ISO/IEC 10646-1:1993, Information technology-Universal Multiple-Octet Coded Character Set (USC)-Part 1: Architecture and Basic Multilingual Plane
[12] ISO/IEC 10646-1:1993/Amd.2:1996, Information technology-Universal Multiple-Octet Coded Character Set (UCS)-Part 1: Architecture and Basic Multilingual Plane-Amendment 2: UCS Transformation Format 8 (UTF-8)
[13] 施可为，蔡安妮，孙景鳌，H．323视频会议终端的软件实现，北京邮电大学学报，2000年第9期
[14] 付良，赵鹏，戴梅萼，史嘉权，在Internet网上提高传输视频实时性的研究，电子技术应用，2000年第7期
[15] ITU-T Recommendation H.450.1, Generic functional protocol for the support of supplementary services in H. 323, 1998.2
[16] Olivier Hersent, David Gurle, Jean-Pierre Petit著，邝坚、戴志涛 译，IP电话——基于分组的多媒体通信系统，人民邮电出版社出版，2000．11
[17] Beau Williamson著，顾金星、张拥军、南亲良 等译，李三运 审校，IP组播网络设计开发(第1卷)，电子工业出版社出版，2000．6
[18] Y. Rekhter, B. Moskowitz, D. Karrenberg, G. J. de Groot and E. Lear, RFC 1918: Address Allocation for Private Internets, 1996.2
[19] 蒋东兴、林鄂华、陈棋德、印敏、刘启新 编著，石碞 审校，Windows Sockets 网络程序设计大全，清华大学出版社，1999
[20] M. Handley, H. Schulzrinne, E. Schooler, J. Rosenberg, RFC 2543: SIP: Session Initiation Protocol, 1999.3
[21] Martin Hall, Dave Treadwell, Mark Towfiq, Windows Sockets 2 Application Programming Interface, Revision 2.2.2, 1997.8
[22] Martin Hall, Dave Treadwell, Mark Towfiq, Windows Sockets 2 Protocol-Specific Annex, Revision 2.0.3, 1996.5
[23] 于波、徐松涛、张中兆，H．323：基于局域网的多媒体通信标准，通信技术，2000年第2期
[24] 程剑峰、吴月珠，桌面视频会议系统技术标准简介，小型微型计算机系统，1998年第11期
[25] 朱秀昌、刘峰 编著，会议电视系统及应用技术，第一版，人民邮电出版社，1999．11
[26] Prabhat K. andleigh & Kiran Thakrar著，徐光佑、史元春 译，多媒体系统设计，第一版，电子工业出版社出版，1998．9
[27] M. TATIPAMULA & B. KHASNABISH编，聂秀英、杨崑、段世惠 译，多媒体通信网络——技术与业务，第一版，人民邮电出版社出版，2001．3
[2] ITU-T Recommendation H.323 v4, Packet-based multimedia communications systems, 2000.11
[3] ITU-T Recommendation H.225.0, Call signalling protocols and media stream packetization for packet based multimedia communication systems, 1999
[4] ITU-T Recommendation H.245, Control protocols for multimedia communication, 2000
[5] ITU-T Recommendation T.120, Data protocols for multimedia conferencing, 1996
[6] ITU-T Recommendation Q.931, ISDN user-network interface layer 3 specification for basic call control, 1998
[7] Trillium Digital Systems, Inc., H. 323 Tutorial
[8] ITU-T Recommendation H.246, Interworking of H-Series multimedia terminals with H-Series multimedia terminals and voice/voiceband terminals on GSTN and ISDN, 1998.2
[9] H. Schulzrinne, S. Casner, R. Frederick, V. Jacobson, RFC 1889: RTP: A Transport Protocol for Real-Time Applications, 1996.1
[10] H. Schulzrinne, RFC 1890: RTP Profile for Audio and Video Conferences with Minimal Control, 1996.1
[11] ISO/IEC 10646-1:1993, Information technology-Universal Multiple-Octet Coded Character Set (USC)-Part 1: Architecture and Basic Multilingual Plane
[12] ISO/IEC 10646-1:1993/Amd.2:1996, Information technology-Universal Multiple-Octet Coded Character Set (UCS)-Part 1: Architecture and Basic Multilingual Plane-Amendment 2: UCS Transformation Format 8 (UTF-8)
[13] 施可为，蔡安妮，孙景鳌，H．323视频会议终端的软件实现，北京邮电大学学报，2000年第9期
[14] 付良，赵鹏，戴梅萼，史嘉权，在Internet网上提高传输视频实时性的研究，电子技术应用，2000年第7期
[15] ITU-T Recommendation H.450.1, Generic functional protocol for the support of supplementary services in H. 323, 1998.2
[16] Olivier Hersent, David Gurle, Jean-Pierre Petit著，邝坚、戴志涛 译，IP电话——基于分组的多媒体通信系统，人民邮电出版社出版，2000．11
[17] Beau Williamson著，顾金星、张拥军、南亲良 等译，李三运 审校，IP组播网络设计开发(第1卷)，电子工业出版社出版，2000．6
[18] Y. Rekhter, B. Moskowitz, D. Karrenberg, G. J. de Groot and E. Lear, RFC 1918: Address Allocation for Private Internets, 1996.2
[19] 蒋东兴、林鄂华、陈棋德、印敏、刘启新 编著，石碞 审校，Windows Sockets 网络程序设计大全，清华大学出版社，1999
[20] M. Handley, H. Schulzrinne, E. Schooler, J. Rosenberg, RFC 2543: SIP: Session Initiation Protocol, 1999.3
[21] Martin Hall, Dave Treadwell, Mark Towfiq, Windows Sockets 2 Application Programming Interface, Revision 2.2.2, 1997.8
[22] Martin Hall, Dave Treadwell, Mark Towfiq, Windows Sockets 2 Protocol-Specific Annex, Revision 2.0.3, 1996.5
[23] 于波、徐松涛、张中兆，H．323：基于局域网的多媒体通信标准，通信技术，2000年第2期
[24] 程剑峰、吴月珠，桌面视频会议系统技术标准简介，小型微型计算机系统，1998年第11期
[25] 朱秀昌、刘峰 编著，会议电视系统及应用技术，第一版，人民邮电出版社，1999．11
[26] Prabhat K. andleigh & Kiran Thakrar著，徐光佑、史元春 译，多媒体系统设计，第一版，电子工业出版社出版，1998．9
[27] M. TATIPAMULA & B. KHASNABISH编，聂秀英、杨崑、段世惠 译，多媒体通信网络——技术与业务，第一版，人民邮电出版社出版，2001．3