臺灣博碩士論文加值系統

現在網路電話越來越流行，許多學校都有專屬的網路電話系統，法令規定也網路電話供應商需提供撥打緊急電話(emergency call)的功能。IETF提出的緊急電話架構，主要是將使用者的位置傳給LoST (Location-to-Service Translation)伺服器，然後找出最近的緊急電話客服中心PSAP (Public Safety Answering Point)。PSAP有固定的負責區域，緊急電話的處理需依使用者的位置接通至負責的PSAP。
因為PSAP尚未被廣泛地部署，所以我們提出DECAP (DNS-SD based Emergency Call Access Point) 網路緊急電話系統來解決校園內撥打網路緊急電話的問題。DECAP的使用者只要按下DECAP UA上的緊急電話按鍵，就可以透過DNS中的資訊找到合適的SIP Proxy Server，然後透過學校的PSTN Gateway把緊急電話引導至轄區警局。我們利用PJSIP Stack與DNS¬-SD SDK來實作DECAP UA，並且提供緊急電話撥話延遲的實驗數據。

Voice over Internet Protocol, also called VoIP, Internet telephony and Broadband telephony is the routing of voice conversations over the Internet or through any other IP-based network. With the increasing of network bandwidth and progress of the network technology, the application of the VoIP is more and more general. A lot of colleges use their own VoIP system to communicate with the inside and outside. The government also request VSP (Voice Service Provider) to supply the functionality of emergency calls. The architecture of emergency call, suggested by the IETF ECRIT, transfers the location of users to LoST (Location-to-Service Translation) Server after users making an emergency call, and then the system will find out the most appropriate PSAP (Public Safety Answering Point) for the user. Each PSAP is responsible for its own service boundaries and the street addresses that it contains. For emergency calling, there are clear jurisdictional responsibilities for service regions.
Because PSAPs have not be set up widely yet, we propose DECAP (DNS-SD based Emergency Call Access Point) for emergency calls over network to solve the problem of making emergency call in the campus. When the users want to make the emergency call, they just need to click the emergency call button on the DECAP UA. The system will query DNS for the information of emergency call service to find the most appropriate SIP Proxy and redirect the emergency call to the responsible police station by the PSTN Gateway in the college.
We implement DECAP UA with PJSIP stack and DNS-SD SDK, and furthermore we provide the experimental results of delay time of dialing emergency call.

中文摘要……………………………………………………… i
英文摘要 ……………………………………………………… ii
誌謝 ……………………………………………………… iii
目錄 ……………………………………………………… iv
表目錄 ……………………………………………………… v
圖目錄 ……………………………………………………… vi
第一章、簡介…………………………………………………1
1.1網路緊急電話………………………………………2
1.2研究動機……………………………………………3
1.3論文架構……………………………………………3
第二章、相關文獻……………………………………………4
2.1網路緊急電話架構…………………………………4
2.2建立緊急通話流程…………………………………5
第三章、DECAP網路緊急電話系統…………………………7
3.1系統架構……………………………………………7
3.2探索緊急電話服務…………………………………8
3.3建立緊急通話………………………………………8
第四章、系統實作……………………………………………10
4.1 Asterisk設定……………………………………10
4.2PSTN Gateway設定…………………………………12
4.3DNS設定……………………………………………13
4.4DECAP UA實作………………………………………15
4.4.1GUI使用者介面……………………………………15
4.4.2DNS-SD元件………………………………………16
4.4.3PJSIP元件…………………………………………17
第五章、範例展示……………………………………………21
5.1Ethereal驗證……………………………………21
5.2Call Setup延遲時間………………………………28
第六章、結論與未來工作……………………………………32
6.1結論…………………………………………………32
6.2未來展望……………………………………………32
參考文獻 ………………………………………………………34

[1]J. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, E. Schooler, SIP: Session Initiation Protocol, RFC 3261,Internet Engineering Task Force, June 2002.
[2]H. Schulzrinne, S. Casner, R. Frederick, V. Jacobson, RTP: A Transport Protocol for Real-Time Applications, RFC1889, Internet Engineering Task Force, January 1996.
[3]B. Rosen, H. Schulzrinne, J. Polk, A. Newton, Framework for Emergency Calling using Internet Multimedia, Internet-Draft, Internet Engineering Task Force, July 2007.
[4]T. Hardie, A. Newton, H. Schulzrinne, H. Tschofenig, LoST: A Location-to-Service Translation Protocol, Internet-Draft, Internet Engineering Task Force, March 2007.
[5]S. Cheshire and M. Krochmal, DNS-Based Service Discovery, Internet-Draft, Internet Engineering Task Force, August 2006.
[6]PJSIP, http://www.pjsip.org.
[7]Asterisk, http://www.asterisk.org.
[8]AudioCodes, http://www.audiocodes.com/.
[9]Bind, http://www.isc.org/index.pl?/sw/bind/.
[10]DHCP, http://www.isc.org/index.pl?/sw/dhcp/.
[11]Bonjour, http://bonjour.macosforge.org/.
[12]Ethereal, http://www.ethereal.com/.