臺灣博碩士論文加值系統

在固接及行動整合網路下，多媒體串流服務是一個關鍵性的應用，然而行動的需求迫使進行中的連線會遭遇跨越不同網路及遷移至不同裝置的問題．目前提出的解決方案大部分都專注在RTSP/RTP上，但由於網路上的安全機制(NATs, firewalls, proxies)會阻隔RTSP/RTP的連線，而HTTP卻通常可以穿越，因此HTTP也是需要被考量的．本論文致力於如何將Session Splice應用於HTTP上，使得就算進行中的連線移動到具有安全機制的不同網路或裝置上，都可以持續的播放．由於Session Splice於RTSP/RTP的做法並無法直接對應到HTTP，所以設計了一個新的機制用來適應HTTP的特性並且不會影響Session Splice本來的優點．更進一步的，我們將其實作於Linux平台中，並由實驗數據可得知Session Splice應用在HTTP上也是可以被現實環境所採用．

The multimedia streaming service is a key application on Fixed-Mobile Convergence (FMC) network. Notwithstanding the mobility requirement will force the ongoing session to meet issues of handoff across interfaces/networks and migration across devices. Approaches, proposed to achieve mobility issues, almost just focused on RTSP/RTP but actually HTTP should be considered because of security policies (NATs, firewalls, proxies) on the Internet blocking RTSP/RTP packets and been usually traversed by HTTP. Hence this thesis is devoted to adapt session splice approach to support HTTP so that ongoing session could be played continuously even moves to networks or devices having security policies. Session splice on RTSP/RTP couldn’t be mapped to HTTP directly therefore a new mechanism is designed to accommodate HTTP and does not affect advantages of session splice. Moreover we have an implementation on the Linux platform and experimental results show that session splice on HTTP could be adopted in the reality.

CONTENTS i
LIST OF TABLES iii
LIST OF FIGURES iv
Chapter 1 Introduction 1
1.1 Overview 1
1.2 Motivation 2
1.3 Contributions 2
1.4 Organization of the Thesis 3
Chapter 2 Background and Related Works 4
2.1 Background 4
2.1.1 HTTP Streaming 4
2.1.2 Metadata Formats for Streaming 6
2.1.2.1 Metadata-Spreading 6
2.1.2.2 Metadata-Gathering 7
2.1.3 Architecture of Divert Socket and Iptables 8
2.2 Related Works 9
2.2.1 Session Splice 9
2.2.2 State of The Art – Handoff 10
2.2.2.1 Network Layer Approaches 10
2.2.2.2 Transport Layer Approaches 11
2.2.3 State of The Art – Session Migration 12
2.2.3.1 Application Layer Approaches 12
2.2.3.2 Proxy-based Approaches 12
Chapter 3 Splicing HTTP Multimedia Session 14
3.1 Overview 14
3.2 Vertical/Horizontal Handoff 18
3.2.1 Host Preparing State 18
3.2.2 Splicing State 19
3.3 Session Migration 20
3.3.1 Preparation on Source Host 20
3.3.2 State Transfer 21
3.3.3 Splicing Procedures on Target Host 21
3.3.3.1 Metadata-Spreading Format 21
3.3.3.2 Metadata-Gathering Format 23
Chapter 4 Implementation 25
4.1 The Mechanism for Monitoring Network Packets 25
4.2 Components for Splicing HTTP Multimedia Session 26
4.3 Re-Construct Metadata 29
4.4 Keeping Migrated Session Started on I Frame 32
Chapter 5 Performance 33
5.1 Configuration 33
5.2 Vertical/Horizontal Handoff Overhead 35
5.2.1 Host Preparing State 35
5.2.2 Splicing State 37
5.3 Session Migration Overhead 38
5.3.1 State Transfer 39
5.3.2 Session Splice State for Metadata-Spreading Case 40
5.3.3 Session Splice State for Metadata-Gathering Case 41
Chapter 6 Conclusions 43
References 44

[1] Fabien Hantz and Julien Herriet, “Multimedia flow transmission policies for collaborative platform based on SOAP,” in IEEE Proceedings of the First International Conference on Distributed Framework for Multimedia Applications, pp. 32-38, 2005. [2] Sujeet Mate, Umesh Chandra, Igor D.D. Curcio, “Movable-Multimedia: Session Mobility in Ubiquitous Computing Ecosystem,” in ACM Proceedings of the 5th International Conference on Mobile and Ubiquitous Multimedia, Vol. 193, December 2006. [3] C. Perkins, “IP Mobility Support for IPv4,” RFC 3344. [4] L.D. Chou and J.M. Chen, “Streaming Media Delivery in Heterogeneous Wireless Networks,” Ph.D Dissertation, National Central University, Taoyouan, Taiwan, July 2006. [5] D. A. Maltz and P. Bhagwat, “MSOCKS: An Architecture for Transport Layer Mobility,” vol. 3, pp. 1037-1045, IEEE INFOCOM 1998. [6] Tadashi Okoshi, Masahiro Mochizuki, Yoshito Tobe, and Hideyuki Tokuda, “MobileSocket: Toward Continuous Operation for Java Applications,” in Proceedings of IEEE International Conference on Computer Communications and Networks, pp. 50–57, Natick, Massachusetts, October 1999. [7] B. Landfeldt, T. Larsson, Y. Ismailov, and A. Seneviratne, “SLM, a Framework for Session Layer Mobility Management,” in Proceedings of the 8th International Conference on Computer Communications and Networks, pp. 452-456, October 1999. [8] C.M. Huang, C.H. Tsai, and M.C Tsai, “Design and Implementation of Video Streaming Hot-Plug between Wired and Wireless Networks Using SCTP,” in The Computer Journal, vol. 49, no. 4, pp. 400-417, June 2006.[9] Yi Cui, Klara Nahrstedt and Dongy An Xu, “Seamless User-Level Handoff in Ubiquitous Multimedia Service Delivery,” Multimedia Tools and Applications Journal (ACM/Kluwer), Special Issue on Mobile Multimedia and Communications and m-Commerce, pp. 137-170, February 2004. [10] P. Bellavesta, A. Corradi, L. Foschini, “MUM: a Middleware for the Provisioning of Continuous Services to Mobile Users,” in Proceedings of the 9th International Symposium on Computers and Communications, pp. 498-505, June 2004. [11] H. Chu, H. Song, C. Wong, K. Kurakake, and M. Katagiri, “ROAM, A seamless Application Framework,” in Journal of Systems and Software, Vol. 69, Issue 3, pp. 209-226, January 2004. [12] M. Hasegawa et al., “Cross-Device Handover Using the Service Mobility Proxy,” in Proceedings of WPMC2003, Yokosuka, Japan, October 2003 [13] Henry Song, Hao-hua Chu, Shoji Kurakake, “Browser Session Preservation and Migration”, Poster Session of WWW Conference, Hawaii, U.S.A., 7-11 May 2002. [14] Zun-Po Huang and Ce-Kuen Shieh, “Using Session Splice Approach to Achieving Multimedia Session Migration,” Master Thesis, National Cheng Kung University, Tainan, Taiwan, July 2007. [15] T.C. Huang, C.K. Shieh, W.H. Lai, and Y.B. Miao, “Session Splice on Multimedia Communication for Mobile Computing,” in IEEE International Conference on Sensor Networks, Ubiquitous, and Trustworthy Computing (SUTC 2006), vol.2, pp. 166-171, June 2006. [16] Oberle Karsten, Wahl Stefan and Sitek Arkadiusz, “Enhanced Methods for SIP b ased Session Mobility in a Converged Network,” Mobile and Wireless Communications Summit, pp. 1-5, July 2007. [17] D. Hoffman et al, “RTP Payload Format for MPEG1/MPEG2 Video,” RFC 2250, January 1998. [18] Y. Kikuchi et al, “RTP Payload Format for MPEG-4 Audio/Visual Streams,” RFC3016, November 2000. [19] J. van der Meer et al, “RTP Payload Format for MPEG-4 Elementary Streams,” RFC 3640, November 2003. [20] S. Wenger et al, “RTP Payload Format for H.264 Video,” RFC 3984, February 2005. [21] R. Fielding et al., “Hypertext Transfer Protocol – HTTP/1.1,” RFC 2616, June 1999. [23] R. Koodli et al., “Mobile IPv4 Fast Handovers,” RFC 4988, October 2007. [22] VideoLAN Client, http://www.videolan.org. [23] Divert Sockets mini-HOWTO, http://www.faqs.org. [24] Ethtool, http://directory.fsf.org/all/ethtool.html.