即時多媒體串流的應用已越來越廣泛，這也是為什麼有許多重疊式網路架構被使用的原因。以對等同儕方式為基礎建構的多媒體串流雛型系統Live2006，提供了可擴充、穩健及高使用率的即時多媒體服務。基於網路應用層多重傳播的概念，以樹狀結構的設計來連接網路各個使用者，使每位使用者能分享所接收到的媒體串流，來降低網路間傳送所產生的流量。Live2006雛型系統不但可有效的減低媒體伺服器原有的負載，並且減少了建構提供大量使用之遠距教學服務所需的成本。此Live2006雛型系統也可使用在家庭或社區網路，並能有效降低網路下載頻寬的使用量，甚至在大量的使用者同時在觀看某一個教學節目(或球賽)時，均能夠提供使用者高品質的視訊服務。另Live2006雛型系統亦提供給在NAT之後，私有IP位址的使用者多媒體串流的服務。因此，使用者能夠藉由各自擁有的設備，在任何時間、任何地點（有網路的環境下），不受限制輕易的收取雛型系統提供的各種節目與資料，當然也包含一些部份資源有限的手持式設備。此外，因為Live2006雛型系統提供的是一個多媒體資料傳送架構平台，它僅需一些改變及調整就可以整合目前現有存在的多媒體遠距教學服務系統。Live2006雛型系統不只可在IPv4環境下運作，並且也可以執行在IPv6網路上，而IPv6的一些特點，如IPv6提供手持式設備的使用服務有較佳的行動力及經由任意傳播服務的能力來提供較好的系統效能，更強化了Live2006雛型系統的功能。
在傳送多媒體資料的方面，雖然網路應用層多重傳播已受到大家的關注與重視，但它仍有一些蠻嚴重的問題尚待解決：多重傳播樹是脆弱的，當某個點（使用者）故障將造成多重傳播樹的裂解，本篇的另一成果就是在對等同儕的即時多媒體串流環境下，提出一個嶄新的階層式環形樹的架構，此架構結合了環狀及樹狀的結構特色，具有穩健的、可靠的、能迅速回復的及可擴充的結構，並且能夠實際被使用作為網路應用層多重傳播架構的型態。當某個點（使用者）進入或離開此系統，此架構能夠快速的回復，如此，即時多媒體串流可在極小的延遲下，非常平順的傳送。此提出的階層式環形樹架構的型態是以非常有效率的方式來建構與管控，並不會在多重傳播樹中有樹分離及合併樹的問題產生，我們藉由實際測試來驗證此架構及演算法的成效，實驗結果顯示儘管在高劇烈變動的對等同儕式網路下，傳送即時多媒體資料，仍然只有很小的延遲及封包遺失率。而在大量數目的網路端點（使用者）進入或離開此系統時，架構的管控不論是在模擬或實測結果，都能得到很低的相關overhead (join overhead, departure overhead and control overhead)，而且架構具備快速回復、提供較佳的多媒體串流服務品質及更為強健的系統結構，並優於ZIGZAG的方法。

The number of live multimedia streaming applications is increasing, explaining the use of many overlay network topologies. A P2P-based multimedia streaming system, called Live2006, provides a scalable, robust, and high available live streaming service. Based on the concept of Application Layer Multicast, a tree-based structure is designed to connect the peers, and the peers share the receiving streaming to reduce network traffic. Live2006 can not only efficiently reduce the loading of the streaming server, but also minimize the cost of constructing a complete distance education system to support large number of users. The proposed Live2006 system can also be established for home or community networks to reduce the usage of downloaded bandwidth. A high level quality of service is maintained even if a significant number of individuals are watching the same program. Live2006 also provides the streaming services for users using the private IP addresses behind an NAT (Network Address Translation). Thus, users can easily access the programs through their devices, including the resource limited handset devices, in anytime and anywhere without constraint. Additionally, since Live2006 is a multimedia data transmission framework, it is easy to integrate with existing distance education service systems with only a few changes. Live2006 not only operates under IPv4 environment, but also works in IPv6 network. Some IPv6 features, such as IPv6 mobility (provides handset users better service) and anycast (provides better system efficiency) even perfects the functionality of Live2006.
Although Application-Layer Multicast (ALM) has attracted much attention in transmitting multimedia, it has a serious problem: the multicast tree is fragile and a peer failure will cause tree partitions. This work presents a novel Hierarchical Ring Tree (HRT) architecture for Peer-to-Peer (P2P) live multimedia streaming. The proposed architecture combines ring-based and tree-based structures in a robust, scalable, reliable and resilient structure that can be used practically as an ALM topology. When peers enter or leave the system, the topology is recovered rapidly such that live multimedia stream can be delivered smoothly with a low latency. The proposed HRT topology is constructed and maintained efficiently without splitting or merging trees. The performance of the proposed architecture and algorithms is evaluated experimentally. Experimental results indicate that the proposed topology can be used in a high-churn P2P network with a small delay. Simulation and experiment results reveal that the proposed architecture has a lower overhead than the ZIGZAG approach when handling peers’ joining or leaving, exhibits faster recovery, better quality of service during streaming, and a more robust topology, even with an extremely large number of peers joining/leaving.

[1] B. Cain, S. Deering, I. Kouvelas, B. Fenner and A. Thyagarajan, Internet Group Management Protocol, Version 3, Request for Comments:3376, October 2002.
[2] B. Quinn and K. Almeroth, IP Multicast Applications: Challenges and Solutions, Request for Comments: 3170, September 2001.
[3] B. Zhang, S. Jaminand, and L. Zhang, Host Multicast: A Framework for Delivering Multicast to End Users, In Proc. of IEEE INFOCOM. The 21st Annual Joint Conference of the IEEE Computer and Communications Societies, June 2002, New York, USA, pp.1366-1375.
[4] D. Ciullo, M.A. Garcia, A. Horvath, E. Leonardi, M. Mellia, D. Rossi, M. Telek, and P. Veglia, Network Awareness of P2P Live Streaming Applications: A Measurement Study, IEEE Transactions on Multimedia, Vol. 12, No. 1, 2010. pp. 57-63.
[5] D. Kostic, A. Rodriguez, J. Albrecht, and A. Vahdat, Bullet: High Bandwidth Data Dissemination Using an Overlay Mesh, In Proc. ACM SOSP’03, New York, USA, Oct. 2003, pp.282-297.
[6] D. Xu, M. Hefeeda, Hambrusch S., and Bhargava B., On Peer-to-Peer media streaming, In Proc. of IEEE International Conference on Distributed Computing Systems (ICDCS'02), July 2002, Vienna, Austria, pp.363-371.
[7] F. Wang, J. Liu, and Y. Xiong, Stable peers: Existence, importance, and application in peer-to-peer live video streaming, In Proc. of IEEE INFOCOM, 2008. pp.1364-1372.
[8] H. Deshpande, M. Bawa, and H. Garcia-Molina, Streaming Live Media Over a Peer-to-Peer Network, Stanford Database Group Technical Report (2001-30), Aug. 2001, Id:501, pp.1-7.
[9] J. Silber, S. Sahu, J. Singh, and Z. Liu, Augmenting Overlay Trees for Failure Resiliency, In Proc. of IEEE GLOBECOM, Dec. 2004, Austin, Texas, pp.1525-1531.
[10] Y. Chu, S.G. Rao, S. Seshan, H. Zhang, Enabling conferencing applications on the Internet using an overlay multicast architecture, In Proc. of ACM SIGCOMM, San Diego, CA USA (2001), pp.55–67.
[11] Z. Liu, Y. Shen, K. W. Ross, S. S. Panwar, and Y. Wang, LayerP2P: Using Layered Video Chunks in P2P Live Streaming, IEEE Transactions on Multimedia, Vol. 11, No. 7, 2009, pp.1340-1352.
[12] A. Rowstron, and P. Druschel, Pastry: Scalable, Distributed Object Location and Routing for Large-scale Peer-to-Peer Systems, In Proc. 18th IFIP/ACM International Conference on Distributed Systems Platforms (Middleware 2001), Nov. 2001, Heidelberg, Germany, pp.329-350.
[13] D. Stolarz, Peer-to-Peer Streaming Media Delivery, In Proc. IEEE International Conference on Peer-to-Peer Computing (P2P 2001), Aug. 2001, Sweden, pp.48-52.
[14] L. Mathy, R. Canonico, and D. Hutchison, An Overlay Tree Building Control Protocol, In Proc. of the 3rd International COST264 Workshop on Networked Group Communication (NGC), Nov 2001, London, UK, pp.76-87.
[15] M. Castro, P. Druschel, A. Kermarrec, and A. Rowstron, SCRIBE: A Large-scale and Decentralized Application-level Multicast Infrastructure, IEEE Journal on Selected Areas in Communications (JSAC), Oct. 2002, pp.1489-1499.
[16] M. Kwon, and S. Fahmy, Topology-aware Overlay Networks for GroupCommunication, In Proc. of ACM NOSSDAV, May 2002, pp. 127-136.
[17] Y. H. Chu, S. G. Rao, and H. Zhang, A Case for End System Multicast, IEEE Journal on Selected Areas in Communications (JSAC), Oct. 2002, pp.1456-1471.
[18] Z. Li, P. Mohapatra, HostCast: A New Overlay Multicasting Protocol, In Proc. of IEEE International Conference on Communications, Vol. 1, 11-15 May 2003, Anchorage, Alaska, pp.702-706.
[19] D. A. Tran, K. A. Hua, and T. Do, ZIGZAG: An Efficient Peer-to-Peer Scheme for Media Streaming, In Proc. of IEEE INFOCOM, Mar. 2003, San Francisco, USA, pp.1283-1292.
[20] D. A., Tran K. A. Hua, and T. Do, A Peer-to-Peer Architecture for Media Streaming, IEEE Journal on Selected Areas in Communications(JSAC), Special Issue on Advances in Overlay Networks, Jan. 2004, pp.121-133.
[21] S. Banerjee, B. Bhattacharjee, and C. Kommareddy, Scalable Application Layer Multicast, In Proc. of ACM SIGCOMM, Aug. 2002, Pittsburgh, PA, pp.205-217.
[22] T. Noguchi, and M. Yamamoto, Construction of a Robust Multicast Tree for Application-level Multicast, In Proc. of IEEE International Conference on Communications, Vol. 1, May 2005, Seoul, Korea, pp.130-135.
[23] D. G. Andersen, H. Balakrishnan,, M.F. Kaashoek,, R. Morris, Resilient overlay networks, In Proc. of the 18th ACM Symposium on Operating System Principles (SOSP’2001), Chateau Lake Louise, Banff, Alberta, Canada (2001), pp.131-145
[24] V. N. Padmanabhan, H. J. Wang, and P. A. Chou, Resilient Peer-to-Peer Streaming, In Proc. of the 11th IEEE International Conference on Network Protocols (ICNP’03), Nov. 2003, Atlanta, Georgia, pp.16-27.
[25] G. Wu, C. Tzi-Cker, Peer to Peer File Download and Streaming, RPE report, TR-185, 2005, pp.1-32.
[26] Http://www.cs.cornell.edu/People/francis/p2p-workshop-v3.pdf
[27] V. Venkataraman, K. Yoshida, and P. Francis, Chunkyspread: Heterogeneous Unstructured Tree-Based Peer-to-Peer Multicast, In Proc. of IEEE ICNP 2006, pp.2-11.
[28] G. Marfia, G. Pau, P. D. Rico, and M. Gerla, P2P Streaming Systems: A Survey and Experiments, 3rd STMicroelectronics STreaming Day (STreaming Day’07) Italy, September, 2007, pp.1-4.
[29] X. Hei, Y. Liu, and K. W. Ross, IPTV over P2P Streaming Networks: The Mesh-Pull Approach, IEEE Communications Magazine, February 2008, pp.86-92.
[30] Q. Huang, H. Jin and X. Liao, P2P Live Streaming with Tree-Mesh based Hybrid Overlay, In Proc. of IEEE ICPPW, 2007, pp.55-60.
[31] N. F. Huang, Y. J. Tzang, H. F. H. Y. Chang, C. W. Ho, “Enhancing P2P Overlay Network Architecture for Live Multimedia Streaming,” Information Sciences, Vol. 180, Issue 17, 2010, pp. 3210-3231.
[32] N. F. Huang, Y. J. Tzang, H. Y. Chang, C. S. Ma, “Construction of an Efficient Ring-Tree-based Peer-to-Peer Streaming Platform,” International Conference on Networked Computing and Advanced Information Management, Seoul, Korea, August 2010, pp. 75-80.
[33] B. Gedik, L. Liu, A Scalable Peer-to-Peer Architecture for Distributed Information Monitoring Applications, IEEE Transactions on Computers, Vol. 54, No.6, June 2005, pp.767-782.
[34] M. Hefeeda, A. Habib, B. Botev, D., Xu and B. Bhargava, PROMISE: A Peer-to-Peer Media Streaming System, In Proc. of ACM Multimedia, Nov. 2003, Berkeley, CA, pp.45-54.
[35] N. F. Huang, Y. J. Tzang, H. F. Chen, and Y. M. Chu, Live Multimedia System Using Peer-to-Peer Architecture for Distance Education, ICWL2006, LNCS, Vol. 4181, Sep. 2006, pp.321-335.
[36] S. Banerjee, C. Kommareddy, K. Kar, B. Bhattacharjee, and S. Khuller, Construction of an Efficient Overlay Multicast Infrastructure for Real-time Applications, In Proc. of IEEE INFOCOM, the 22nd Annual Joint Conference of the IEEE Computer and Communications Societies, March 2003, San Francisco, CA, pp.1521-1531.
[37] X. Liao, H. Jin, Y. Liu, L. M. Ni, and D. Deng, AnySee : peer-to-peer live streaming, In Proc. of IEEE INFOCOM, April 2006.
[38] X. Zhang, J. Liu, B. Li, and T.-S. P. Yum, CoolStreaming/DONet: A Data-driven Overlay Network for Live Media Streaming, In Proc. of IEEE INFOCOM, Miami, USA, March 2005, Vol. 3, pp.2102-2111.
[39] D. Pendarakis, S. Shi, D. Verma, and M. Waldvogel, ALMI: An Application Level Multicast Infrastructure, In Proc. of the 3rd USENIX Symposium on Internet Technologies and Systems (USITS 2001), March 2001, San Francisco, CA, USA, pp.49-60.
[40] M. Castro, P. Druschel, A. Kermarrec, A. Nandi, A. Rowstron, and A. Singh, Splitstream: High-bandwidth Multicast in Cooperative Environments, In Proc. of the 19th ACM Symposium on Operating Systems Principles (SOSP 2003), Bolton Landing, New York, USA, pp.298-313.
[41] PlanetLab website, http://www.planet-lab.org/, 2010
[42] V. N. Padmanabham, H. J. Wang, P. A. Chou, and K. Sripanidkulchai, Distributing Streaming Media Content Using Cooperative networking, In Proc. of ACM NOSSDAV, May 2002, pp.177-186.
[43] X. Jiang, Y. Dong, D. Xu, and B. Bhargava, GunStream: A P2P Media Streaming Prototype, In Proc. of IEEE International Conference on Multimedia & Expo, July 2003, Vol. 2, pp.325-328.
[44] T. Small, B. Li, and B. Liang, Outreach: Peer-to-Peer Topology Towards Minimized Server Bandwidth Costs, IEEE Journal on Selected Areas in Communications (JSAC), Jan. 2007, pp.35-45.
[45] Y.-H. Kim, S.-G. Kang and H.-S. Kim, Efficient Tree Management for Resilient Overlay Multicast, In Proc. of IEEE ICACT, Feb. 2009, pp.373-377.
[46] W. Wang and H.-Y. Zhang, Study on Application Layer Multicast Technology Based on P2P Streaming Media System, In Proc. of IEEE CNMT, Dec. 2009, pp.1-4.
[47] L. Lao, J. Cui, and S. Chen, A Scalable Overlay Multicast Architecture for Large-scale Applications, IEEE Transactions on Parallel and Distributed Systems, Vol. 18, No. 4, April 2007, pp.449-459.
[48] Z. Chen, B. Li, G. Keung, H. Yin, C. Lin and Y. Wang, How Scalable could P2P Live Media Streaming System be with the Stringent Time Constraint? In Proc. of IEEE ICC, 2009, pp.1-5.
[49] N. Magharei, R. Rejaie and Y. Guo, Mesh or Multiple-Tree: A Comparative Study of Live P2P Streaming Approaches, In Proc. of IEEE INFOCOM, 2007, pp.1424-1432.
[50] Q. Zhu, R. Wang, D. Qian and F. Xiao, Re-exploring the Potential of using Tree Structure in P2P Live Streaming Networks, In Proc. of IEEE IFIP, June 2009, pp.125-132.
[51] D. Ren, Y.-T. Li and S.-H. Chan, Fast-Mesh: A Low-Delay High-Bandwidth Mesh for Peer-to-Peer Live Streaming, IEEE Transactions on Multimedia, Vol. 11, No. 8, 2009, pp.1446-1456.
[52] Z. Lu, Y. Li, J. Wu, S. Zhang and Y. Zhong, MultiPeerCast: A Tree-mesh-hybrid P2P Live Streaming Scheme Design and Implementation based on PeerCast, IEEE International Conference on High Performance Computing and Communications, 2008, pp.714-719.
[53] H. Byun and M. Lee, HyPO: A Peer-to-Peer based Hybrid Overlay Structure, In Proc. of IEEE ICACT, 2009, pp.840-844.
[54] S. Awiphan, Z. Su and J. Katto, ToMo: A Two-layer Mesh/Tree Structure for Live Streaming in P2P Overlay Network, In Proc. of IEEE CCNC, 2010, pp.1-5.
[55] J. Yue and C. Wu, A Trees-Mesh based Application Layer Multicast Using Collaborative Sub-streams, IEEE International Conference on Future Networks, 2010, pp.29-33.
[56] F. Wang, Y. Xiong and J. C. Liu, mTreebone: A Hybrid Tree/Mesh Overlay for Application-Layer Live Video Multicast, In Proc. of IEEE ICDCS, 2007, pp.49-56.
[57] F. Wang, Y. Xiong and J. Liu, mTreebone: A Collaborative Tree-Mesh Overlay Network for Multicast Video Streaming, IEEE Transactions on Parallel and Distributed Systems, Vol. 21, No. 8, March 2010, pp.379-392.
[58] Z. Liu, Y. Shen, K. W. Ross, S. S. Panwar and Y. Wang, LayerP2P: Using Layered Video Chunks in P2P Live Streaming, IEEE Transactions on Multimedia, Vol. 11, No. 7, 2009, pp.1340-1352.
[59] H. Guo, K.-T. Lo, Y. Qian and J. Li, Peer-to-Peer Live Video Distribution under Heterogeneous Bandwidth Constraints, IEEE Transactions on Parallel and Distributed Systems, Vol. 20, No. 2, March 2009, pp.233-245.
[60] A. Matrawy, I. Lambadaris, A Real-Time Video Multicast Architecture for Assured Forwarding Services, IEEE Transactions on Multimedia, Vol. 7, No. 4, Aug. 2005, pp.688-699.
[61] W.-H. Lee, S.-S. Tseng, and W.-Y. Shieh, Collaborative real-time traffic information generation and sharing framework for the intelligent transportation system, Information Sciences, Vol. 180, No. 1, Jan. 2010, pp. 62-70.
[62] C. Partridge, T. Mendez, W. Milliken, Host Anycasting Service, Request for Comments: 1546, (1993)
[63] S.-Y. Tseng, Y.-M. Hung, and C.-C. Lin, Genetic Algorithm for Delay- and Degree-contrained Multimedia Broadcasting on Overlay Networks, Computer Communications, 2006, pp.3625-3632.
[64] B. Ye, M. Guo, D. Chen, and S. Lu, A Degree-constrained QoS-aware Routing Algorithm for Application Layer Multicast, Information Sciences, Vol. 177, No. 17, Sep. 2007, pp.3613-3626.
[65] H.-C. Hsiao and C.-P. He, A Tree-Based Peer-to-Peer Network with Quality Guaratees, IEEE Transactions on Parallel and Distributed Systems, Vol. 19, no. 8, Aug. 2008, pp. 1099-1110.
[66] S. Liu, Z. S. Rui, W. Jiang, J. Rexford, and M. Chiang, Performance Bounds for Peer-Assisted Live Streaming, In Proc. of ACM SIGMETRICS, June, 2008, Annapolis, Maryland, USA. pp.313-324.
[67] The Network Simulator – NS2 http://www.isi.edu/nsnam/ns/, 2010.
[68] E.W. Zegura, K.L. Calvert, and Bhattacharjee S., How to Model an Internetwork, In Proc. of IEEE INFOCOM, March 1996, San Francisco, CA, USA, pp.594-602.