层次化可扩展可靠组播研究及其在分布式组播发言权控制中的应用
|
摘要
当今，多媒体会议正向着基于IP组播的大规模、大范围、分布式的方向发展。但是由于组播传输是不可靠的，所以难以实现基于组播的会议控制。其结果是现有的会议系统或者保持传统的集中式会议控制结构，只将组播技术用于向没有交互权的接收者发送媒体数据；或者放弃会议控制，将组播技术应用于小规模松散型交互。目前，组播技术的这两种应用方式都不能很好地发挥它给多媒体会议带来的在可扩展性和鲁棒性方面的巨大提升潜力。因此组播会议也就达不到它所应具有的可扩展性。为了解决这个问题，我们提出基于可靠组播实现分布式会议控制，其核心是设计适合分布式组播会议控制的可靠组播通信模型。本文从分布式组播会议控制对网络通信的要求出发，在对影响可靠组播性能的因素进行深入分析基础上，融合现有可靠组播协议的优秀思想，提出了一个新的基于接收方丢失报文概率分组的层次化可扩展可靠组播通信模型HSRM(Hierarchical Scalable Reliable Multicast)。并根据“分布”、“动态”、“公平”、“自治”等原则，设计了HSRM层次化结构的动态构建和维护机制，最后将它与三个经典可靠组播协议进行了比较。HSRM使用全分布方式和一致的组播通信构造与发送者无关的层次结构，限制了反馈和修复报文的扩散范围并减小了组内节点的异构性和组播组的规模。在保持良好的可扩展性、鲁棒性和灵活性的前提下，提高了多对多可靠组播的性能。在HSRM的基础上，我们结合基于IP组播的协同学习环境WebLearning+的应用需求，设计了一个分布式组播发言权控制工具。该工具协议一致，支持灵活的会议结构，失效恢复简单，支持与会者自由加入和退出，有很好的可扩展性和鲁棒性。
本文的贡献体现在以下几个方面：
1．提出了一个新的面向分布式组播会议控制的可靠组播通信模型HSRM。
2．通过理论分析和数值实验，研究了影响可靠组播性能的主要因素及其影响程度和变化规律。其结果对于正确建立层次化可靠组播模型分组的原则具有普遍意义。
3．设计了动态构建和维护HSRM层次化结构的分布式、自适应算法，对构造其它层次化可靠组播模型具有一定程度的借鉴意义。
4．设计了一个基于可靠组播协议HSRM的分布式组播发言权控制工具。
In recent years,the multicast-based conference that includes a large number of hosts and covers a large scope of network is the main development direction of the multimedia conferencing. However,IP multicast is generally unreliable,disordered and with redundant copies,and there is no reliable multicast protocol designed for multicast-based conference control. As a result,it is quite difficult to realize conference control basing multicast. As to the existing multicast-based conference systems,two choices are widely adopted:to keep the traditional centralized conference control structure with multicast only used for sending media data to those receivers who can't interact with others;or to give up conference control at all with multicast used for interactive loosely coupled sessions including a small quantity of hosts. Neither of the two choices can take the advantages of multicast to improve the scalability and robusticity of multimedia conferencing actually. In order to solve this problem,a reliable multica
st communication model for conference control is designed specially. We firstly study the requirements of multicast-based conference control,then analysis the main factors to the performance of reliable multicast. Subsequently we present a new reliable multicast protocol named HSRM (Hierarchical Scalable and Reliable Multicast) according to the receivers' packet loss probabilities. Furthermore,we present a distributed self-adaptive mechanism to construct and maintain the hierarchical structure of HSRM dynamically according to a series of criterions such as distributed,dynamical,fair and so on. At last,the comparisons to several well-known multicast protocols SRM,RMTP and TMTP are given. HSRM constructs hierarchical structure basing multicast communication completely and its structure has no relationship with the senders. The spread of feedback and recovery packets are restricted efficiently. The heterogeneity and the size of multicast sub-groups are also decreased. In a word,the performance of the multipoint
-to-multipoint reliable multicast is improved,without bad effect on the robusticity,scalability and flexibility. We then present a HSRM-based distributed floor control model to accommodate the application background of WebLearning+,an IP-multicast based collaborative learning system. This floor control model is flexible,scalable and robust. It supports late joining,early leaving and crash recovery.
本文的贡献体现在以下几个方面：
1．提出了一个新的面向分布式组播会议控制的可靠组播通信模型HSRM。
2．通过理论分析和数值实验，研究了影响可靠组播性能的主要因素及其影响程度和变化规律。其结果对于正确建立层次化可靠组播模型分组的原则具有普遍意义。
3．设计了动态构建和维护HSRM层次化结构的分布式、自适应算法，对构造其它层次化可靠组播模型具有一定程度的借鉴意义。
4．设计了一个基于可靠组播协议HSRM的分布式组播发言权控制工具。
In recent years,the multicast-based conference that includes a large number of hosts and covers a large scope of network is the main development direction of the multimedia conferencing. However,IP multicast is generally unreliable,disordered and with redundant copies,and there is no reliable multicast protocol designed for multicast-based conference control. As a result,it is quite difficult to realize conference control basing multicast. As to the existing multicast-based conference systems,two choices are widely adopted:to keep the traditional centralized conference control structure with multicast only used for sending media data to those receivers who can't interact with others;or to give up conference control at all with multicast used for interactive loosely coupled sessions including a small quantity of hosts. Neither of the two choices can take the advantages of multicast to improve the scalability and robusticity of multimedia conferencing actually. In order to solve this problem,a reliable multica
st communication model for conference control is designed specially. We firstly study the requirements of multicast-based conference control,then analysis the main factors to the performance of reliable multicast. Subsequently we present a new reliable multicast protocol named HSRM (Hierarchical Scalable and Reliable Multicast) according to the receivers' packet loss probabilities. Furthermore,we present a distributed self-adaptive mechanism to construct and maintain the hierarchical structure of HSRM dynamically according to a series of criterions such as distributed,dynamical,fair and so on. At last,the comparisons to several well-known multicast protocols SRM,RMTP and TMTP are given. HSRM constructs hierarchical structure basing multicast communication completely and its structure has no relationship with the senders. The spread of feedback and recovery packets are restricted efficiently. The heterogeneity and the size of multicast sub-groups are also decreased. In a word,the performance of the multipoint
-to-multipoint reliable multicast is improved,without bad effect on the robusticity,scalability and flexibility. We then present a HSRM-based distributed floor control model to accommodate the application background of WebLearning+,an IP-multicast based collaborative learning system. This floor control model is flexible,scalable and robust. It supports late joining,early leaving and crash recovery.
引文
[1] 单玉峰，柴乔林，肖宗水．交互式IP组播技术及其在多点视频会议中的应用研究．计算机工程与应用，2000，36(8)：125-128．
[2] Beau Williamson，顾金星 等译．IP组播网络设计开发(第1卷)．北京：电子工业出版社，2000．
[3] N. LBNL. Vat: LBNL Audio Conferecing Tool. 1995. ftp://ftp.ee.lbl.gov/conferencing/vat.
[4] S. McCanne, V. Jacobson. vic: A Flexible Framework for Packet Video. ACM Multimedia, 1995: 511-522.
[5] H. Schulzrinne. Guide to Ne VoT 3.28. GMD Fokus, 1995.
[6] T. Turletti. The INRIA videoconferencing system (ivs). ConneXions-The Interoperability Report, 1994, 8(10): 20-24.
[7] R. Frederick. Experiences with real-time software video compression. In Sixth International Workshop on Packet Video, 1994.
[8] V. Jacobson, S. McCanne. LBL Whiteboard: wb. Lawrence Berkeley Laboratory. ftp://ftp.ee.lbl.gov/conferencing/wb.
[9] 卢官明．Internet上多媒体会议系统的相关协议．世界网络与多媒体，2000，8(7)：29-32．
[10] International Telecommunication Union. H.323 extended for loosely coupled conferences. Recommendation H.332, Telecommunication Standardization Sector of ITU, Geneva, Switzerland, 1998.
[11] M. Handley, I. Wakeman, J. Crowcroft. The conference control protocol (CCCP): a scalable base for building conference control applications. SIGCOMM Symposium on Communications Architectures and Protocols, 1995.
[12] C. Bormann, J. Ott, C. Reichert. SCCP: Simple Conference Control Protocol. INTERNET-DRAFT draft-ietf-mmusic-sccp-00.txt, 1996.
[13] R. MALPANI, L.A. ROWE. Floor Control for Large-Scale MBONE Seminars. Proceedings of The Fifth Annual ACM International Multimedia Conference, 1997: 155-163.
[14] Y. CHAWATHE, H. WANG A Coordination Architecture for MBone Conferences. U.C. Berkeley CS268 Computer Networks Course Project Report, 1997.
[15] D. Towsley, J. Kurose, S. Pingali. A Comparison of sender and receiver-initiated reliable multicast protocols. JSAC, 1997, 15(3).
[16] Sridhar Pingali, Don Towsley, James F. Kurose. A Comparison of Sender-Initiated and Receiver-Initiated Reliable Multicast Protocols. Proceedings of the Sigmetrics Conference on Measurement and Modeling of Computer Systems. New York: ACM Press, 1994.
[17] B. Levine, J. Garcia-Luna-Aceves. A comparison of known classes of reliable multicast protocols. Proc. IEEE International Conference on Network Protocols, 1996.
[18] Floyd S, Jacobson V, McCanne S, ed. A reliable multicast framework for light-weight sessions and application level framing. IEEE\slash ACM Transactions on Networking, 1997, 5(6): 784-803.
[19] Brian Whetten, Todd Montgomery, Simon M. Kaplan A High Performance Totally Ordered Multicast Protocol. Dagstuhl Seminar on Distributed Systems. 1994: 33-57.
[20] John C., H. Lin, Sanjoy Paul. RMTP: A Reliable Multicast Transport Protocol. INFOCOM (3), 1996: 1414-1424.
[21] Rajendra Yavatkar, James Griffoen, Madhu Sudan. A Reliable Dissemination Protocol for Interactive Collaborative Applications. ACM Multimedia, 1995: 333-344.
[22] Koifman A, Zabele S. RAMP: A reliable adaptive multicast protocol. IEEE Infocom'96, 1996: 1442-1451.
[23] Hugh W. Holbrook, Sandeep K. Singhal, David R. Cheriton. Log-Based Receiver-Reliable Multicast for Distributed Interactive Simulation. SIGCOMM, 1995: 328-341.
[24] 吴文峻，聂树宣．可靠组播研究综述．计算机科学，2001，28(2)：58-62．
[25] Philip A. Chou, Alexander E. Mohr, Albert Wang, ed. FEC and Pseudo-ARQ for Receiver-Driven Layered Multicast of Audio and Video. Data Compression Conference, 2000: 440-449.
[26] Gemmell J. Scalable Reliable Multicast Using Erasure-Correcting Re-sends. Special Issue for Multipoint Communications, 1997, 15: 288-290.
[27] 赵东升，卢锡城，周兴铭．基于集成FEC和层次传输的可靠组播的流控技术．计算机学报，1999，22(1)：86-91．
[28] 蔡洪斌，杨国纬，周明天．用追加发送技术实现可靠多播通信．小型微型计算机系统，2000，21(4)：427-431．
[29] J. Nonnenmacher, E. Biersack. Reliable multicast: Where to use FEC. Proceedings of IFIP 5th International Workshop on Protocols for High Speed Networks. 1996.
[30] Jorg Nonnenmacher, Martin S. Lacher, Matthias Jung, ed. How Bad is Reliable Multicast without Local Recovery?. INFOCOM, 1998(3): 972-979.
[31] 杨永高，潘启敬．适用于分布式虚拟环境的MULTICAST通信协议的设计与分析．小型微型计算机系统，1999，20(3)：171—175．
[32] N. Kausar, J. Crowcroft. An architecture of conference control functions. Proc. of Photonics East, SPIE, 1999.
[33] M. HANDLEY, I. WAKEMAN. CCCP: Conference Control Channel Protocol. SIGCOMM, 1995.
[34] R. MALPANI, L.A. ROWE. Floor Control for Large-Scale MBONE Seminars. Proceedings of The Fifth Annual ACM International Multimedia Conference, 1997: 155-163.
[35] H. Dommel, J. Garcia-Luna-Aceves. Floor control for networked multimedia applications. ACM SIGCOMM'95 Middleware Workshop, 1995.
[36]高旭，沈苏彬，顾冠群．多媒体会议系统的发言权控制协议研究，计算机学报，2001，24(8)：845—852．
[37]王晖，黄英君，姜志宏等．WebLearning：一个基于园区网的远程教学系统．第九届全国多媒体技术学术会议论文集，2000．
[38]张鑫，黄英君，王晖等．实时远程教学系统中学生反馈子系统的设计与实现．第九届全国多媒体技术学术会议论文集，2000．
[39]姜宁康，李毓麟．NS网络仿真技术及其应用分析．小型微型计算机系统，2001，22(4)：415-417．
[2] Beau Williamson，顾金星 等译．IP组播网络设计开发(第1卷)．北京：电子工业出版社，2000．
[3] N. LBNL. Vat: LBNL Audio Conferecing Tool. 1995. ftp://ftp.ee.lbl.gov/conferencing/vat.
[4] S. McCanne, V. Jacobson. vic: A Flexible Framework for Packet Video. ACM Multimedia, 1995: 511-522.
[5] H. Schulzrinne. Guide to Ne VoT 3.28. GMD Fokus, 1995.
[6] T. Turletti. The INRIA videoconferencing system (ivs). ConneXions-The Interoperability Report, 1994, 8(10): 20-24.
[7] R. Frederick. Experiences with real-time software video compression. In Sixth International Workshop on Packet Video, 1994.
[8] V. Jacobson, S. McCanne. LBL Whiteboard: wb. Lawrence Berkeley Laboratory. ftp://ftp.ee.lbl.gov/conferencing/wb.
[9] 卢官明．Internet上多媒体会议系统的相关协议．世界网络与多媒体，2000，8(7)：29-32．
[10] International Telecommunication Union. H.323 extended for loosely coupled conferences. Recommendation H.332, Telecommunication Standardization Sector of ITU, Geneva, Switzerland, 1998.
[11] M. Handley, I. Wakeman, J. Crowcroft. The conference control protocol (CCCP): a scalable base for building conference control applications. SIGCOMM Symposium on Communications Architectures and Protocols, 1995.
[12] C. Bormann, J. Ott, C. Reichert. SCCP: Simple Conference Control Protocol. INTERNET-DRAFT draft-ietf-mmusic-sccp-00.txt, 1996.
[13] R. MALPANI, L.A. ROWE. Floor Control for Large-Scale MBONE Seminars. Proceedings of The Fifth Annual ACM International Multimedia Conference, 1997: 155-163.
[14] Y. CHAWATHE, H. WANG A Coordination Architecture for MBone Conferences. U.C. Berkeley CS268 Computer Networks Course Project Report, 1997.
[15] D. Towsley, J. Kurose, S. Pingali. A Comparison of sender and receiver-initiated reliable multicast protocols. JSAC, 1997, 15(3).
[16] Sridhar Pingali, Don Towsley, James F. Kurose. A Comparison of Sender-Initiated and Receiver-Initiated Reliable Multicast Protocols. Proceedings of the Sigmetrics Conference on Measurement and Modeling of Computer Systems. New York: ACM Press, 1994.
[17] B. Levine, J. Garcia-Luna-Aceves. A comparison of known classes of reliable multicast protocols. Proc. IEEE International Conference on Network Protocols, 1996.
[18] Floyd S, Jacobson V, McCanne S, ed. A reliable multicast framework for light-weight sessions and application level framing. IEEE\slash ACM Transactions on Networking, 1997, 5(6): 784-803.
[19] Brian Whetten, Todd Montgomery, Simon M. Kaplan A High Performance Totally Ordered Multicast Protocol. Dagstuhl Seminar on Distributed Systems. 1994: 33-57.
[20] John C., H. Lin, Sanjoy Paul. RMTP: A Reliable Multicast Transport Protocol. INFOCOM (3), 1996: 1414-1424.
[21] Rajendra Yavatkar, James Griffoen, Madhu Sudan. A Reliable Dissemination Protocol for Interactive Collaborative Applications. ACM Multimedia, 1995: 333-344.
[22] Koifman A, Zabele S. RAMP: A reliable adaptive multicast protocol. IEEE Infocom'96, 1996: 1442-1451.
[23] Hugh W. Holbrook, Sandeep K. Singhal, David R. Cheriton. Log-Based Receiver-Reliable Multicast for Distributed Interactive Simulation. SIGCOMM, 1995: 328-341.
[24] 吴文峻，聂树宣．可靠组播研究综述．计算机科学，2001，28(2)：58-62．
[25] Philip A. Chou, Alexander E. Mohr, Albert Wang, ed. FEC and Pseudo-ARQ for Receiver-Driven Layered Multicast of Audio and Video. Data Compression Conference, 2000: 440-449.
[26] Gemmell J. Scalable Reliable Multicast Using Erasure-Correcting Re-sends. Special Issue for Multipoint Communications, 1997, 15: 288-290.
[27] 赵东升，卢锡城，周兴铭．基于集成FEC和层次传输的可靠组播的流控技术．计算机学报，1999，22(1)：86-91．
[28] 蔡洪斌，杨国纬，周明天．用追加发送技术实现可靠多播通信．小型微型计算机系统，2000，21(4)：427-431．
[29] J. Nonnenmacher, E. Biersack. Reliable multicast: Where to use FEC. Proceedings of IFIP 5th International Workshop on Protocols for High Speed Networks. 1996.
[30] Jorg Nonnenmacher, Martin S. Lacher, Matthias Jung, ed. How Bad is Reliable Multicast without Local Recovery?. INFOCOM, 1998(3): 972-979.
[31] 杨永高，潘启敬．适用于分布式虚拟环境的MULTICAST通信协议的设计与分析．小型微型计算机系统，1999，20(3)：171—175．
[32] N. Kausar, J. Crowcroft. An architecture of conference control functions. Proc. of Photonics East, SPIE, 1999.
[33] M. HANDLEY, I. WAKEMAN. CCCP: Conference Control Channel Protocol. SIGCOMM, 1995.
[34] R. MALPANI, L.A. ROWE. Floor Control for Large-Scale MBONE Seminars. Proceedings of The Fifth Annual ACM International Multimedia Conference, 1997: 155-163.
[35] H. Dommel, J. Garcia-Luna-Aceves. Floor control for networked multimedia applications. ACM SIGCOMM'95 Middleware Workshop, 1995.
[36]高旭，沈苏彬，顾冠群．多媒体会议系统的发言权控制协议研究，计算机学报，2001，24(8)：845—852．
[37]王晖，黄英君，姜志宏等．WebLearning：一个基于园区网的远程教学系统．第九届全国多媒体技术学术会议论文集，2000．
[38]张鑫，黄英君，王晖等．实时远程教学系统中学生反馈子系统的设计与实现．第九届全国多媒体技术学术会议论文集，2000．
[39]姜宁康，李毓麟．NS网络仿真技术及其应用分析．小型微型计算机系统，2001，22(4)：415-417．
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |