VOIP系统的实现及Radius协议在其中的应用
摘要
网络和多媒体技术的飞速发展使得基于Internet的增值服务越来越多，在IP网上传输语音就是其中的一种，而IP电话是其中主要的应用。本文所研究的这套VOIP系统就是为更好的解决在Internet上传输语音的问题的，其主要目的是给用户带来通话质量好，价格低廉的语音通信服务。
VOIP系统的关键问题是如何实现一套结构合理、性能优良的系统和如何保证准确、实时的认证计费。我们的系统是以中国联通浙江分公司的VOIP系统架构为硬件基础，在综合考虑了以上关键问题后研究开发的。归纳起来，本文主要进行了以下研究工作。
(1)提出了一套结构合理、性能优良的VOIP系统结构。
(2)详细分析了认证计费协议—Radius，对其存在的问题和不足之处给出了改进方法，并在系统中实现了该协议。
(3)对系统进行了测试并给出了测试结果，对其中存在的问题作了的分析，并给出了改进意见。
本文研究的系统已应用于实际，具体可访问网站www.telsoft.com.cn.
With the rapid development of network and multimedia technology, more and more Internet value add services appear. One of them is voice over IP (VOIP) and IP phone is the mainly application.
One of the key points about VOIP is to design a system with advisable architecture and excellent performance; the other is to assure accurate authtication and real time accounting. The telsoft VOIP system is based on the hardware configure of VOIP system of Zhejiang branch office China Unicom. The main contributions of the paper are as follow:
(1) Developed one VOIP system with advisable architecture and excellent performance.
(2) Analysed the Radius protocol in detail, put forward some improvement methods and implemented the protocol in the system.
(3) Had a thoroughly test to the whole system, discussed the drawback of the system and presented improvement suggestions.
VOIP系统的关键问题是如何实现一套结构合理、性能优良的系统和如何保证准确、实时的认证计费。我们的系统是以中国联通浙江分公司的VOIP系统架构为硬件基础，在综合考虑了以上关键问题后研究开发的。归纳起来，本文主要进行了以下研究工作。
(1)提出了一套结构合理、性能优良的VOIP系统结构。
(2)详细分析了认证计费协议—Radius，对其存在的问题和不足之处给出了改进方法，并在系统中实现了该协议。
(3)对系统进行了测试并给出了测试结果，对其中存在的问题作了的分析，并给出了改进意见。
本文研究的系统已应用于实际，具体可访问网站www.telsoft.com.cn.
With the rapid development of network and multimedia technology, more and more Internet value add services appear. One of them is voice over IP (VOIP) and IP phone is the mainly application.
One of the key points about VOIP is to design a system with advisable architecture and excellent performance; the other is to assure accurate authtication and real time accounting. The telsoft VOIP system is based on the hardware configure of VOIP system of Zhejiang branch office China Unicom. The main contributions of the paper are as follow:
(1) Developed one VOIP system with advisable architecture and excellent performance.
(2) Analysed the Radius protocol in detail, put forward some improvement methods and implemented the protocol in the system.
(3) Had a thoroughly test to the whole system, discussed the drawback of the system and presented improvement suggestions.
引文
[1] http://www.hrbs.net/cgi-bin/bbscha.p1?title=118&hidden=board7.
[2] http://www.c114.net/study/voip/voip.htm.
[3] 《IP Telephony: The Integration of Robust VOIP Services》 (美) Bill Douskalis 机械工业出版社．
[4] http://www.chinaunicom.com.cn/product/product_ip.asp.
[5] C.Rigney, S.Willens, A.Rubens, etc. Network Working Group RFC 2865, June 2000.
[6] C.Rigney. Network Working Group RFC 2866, June 2000.
[7] 《IP电话技术及其应用》舒华英 赖平漳等编著 人民邮电出版社．
[8] http://www.ctiforum.com/train/cttech/voip/voip 001.htm.
[9] 许城，姚兆平．VOIP与TMD的网络成本比较．电信科学，1999(12)．
[10] http://www.chinagk.org/technology.htm.
[11] 李琳，柴乔林，袁春阳．H.323与SIP在VOIP应用中的实现及比较．计算机应用，2002(9)，Vol．22．
[12] 《IP电话与IP电话技术基础》陈俊良 主编 机械工业出版社．
[13] Baker, Maurice R. Speech transport for packet telephony and voice over IP.Proceedings of the 1999 Internet Ⅱ: Qaulity of Service and Future Directions, 1999.
[14] Mouchtaris, P. (Ed.). Voice over IP (VoIP) technology. Sponsor: SPIE,Conference Title: Voice Over IP (VoIP) Technology, 2001.
[15] H. Schulzrinne, S. Casner, R. Frederick, etc. Audio-Video Transport Working Group RFC 1889(RTP), January 1996.
[16] Markopoulou, Athina P.;Tobagi, Fouad A.;Karam, Mansour J. Assessment of VoIP quality over internet backbones. IEEE Infocom 2002, 2002.
[17] 汪亚光，汪敏．包头压缩技术在VOIP中的应用．上海大学学报，2001(1)，Vol．7．
[18] 黄永峰，周可，张江陵．IP电话系统中的消回声处理．数据采集与处理，2000(4)，Vol．15．
[19] ITU-T Telecommunication Standardization Sector, Recommendation H.323V2, Feb. 1998.
[20] ITU-T Telecommunication Standardization Sector, Recommendation H.245V3,June. 1996.
[21] ITU-T Telecommunication Standardization Sector, Recommendation H.225.0V3,May. 1996.
[22] 《因特网语音通信技术及其应用》黄永峰 编 人民邮电出版社．
[23] Liu, Xicheng; Li, Timothy J. Implementation of a prototype VoIP systems Journal of Computer Science and Technology, Sep 2000.
[24] Anquetil, Laurent Philippe;Bonnet, Gilles;Lapierre, Martine;Van Leekwijck,Werner;Willekens, Guido. New multimedia services using a server architecture. Alcatel Telecommunications Review, 2000.
[25] 云红艳，高岭，李祥生．远程访问系统中Radius的应用．西北大学学报，2000(3)，Vol．30．
[26] 《通信网的安全—理论与技术》王育民 刘建伟编著 西安电子科技大学出版社．
[27] http://www.justdn.org/justdn.v2/print.php?ID=193.
[28] Cisco公司《RADIUS Vendor-Specific Attributes Voice Implementation Guide》.http://www.cisco.com/univercd/cc/td/doc/product/access/acs serv/vapp dev/vsaig3.pdf.
[29] 侯艳，钟宝荣．VOIP电话系统的数据库系统的备份与恢复．计算机与现代化，2002(1)，Vol．77．
[30] Kos, Anton;Klepec, Borut;Tomazic, Saso. Techniques for performance improvement of VoIP applications. 11th IEEE Mediterranean Electronical Conference (Melecon 2002), 2002.
[31] M.Leech, M.Ganis, Y. Lee, etc. Network Working Group RFC 1928(SOCKS v5),March 1996.
[32] http://www.socks.permeo.com.
[2] http://www.c114.net/study/voip/voip.htm.
[3] 《IP Telephony: The Integration of Robust VOIP Services》 (美) Bill Douskalis 机械工业出版社．
[4] http://www.chinaunicom.com.cn/product/product_ip.asp.
[5] C.Rigney, S.Willens, A.Rubens, etc. Network Working Group RFC 2865, June 2000.
[6] C.Rigney. Network Working Group RFC 2866, June 2000.
[7] 《IP电话技术及其应用》舒华英 赖平漳等编著 人民邮电出版社．
[8] http://www.ctiforum.com/train/cttech/voip/voip 001.htm.
[9] 许城，姚兆平．VOIP与TMD的网络成本比较．电信科学，1999(12)．
[10] http://www.chinagk.org/technology.htm.
[11] 李琳，柴乔林，袁春阳．H.323与SIP在VOIP应用中的实现及比较．计算机应用，2002(9)，Vol．22．
[12] 《IP电话与IP电话技术基础》陈俊良 主编 机械工业出版社．
[13] Baker, Maurice R. Speech transport for packet telephony and voice over IP.Proceedings of the 1999 Internet Ⅱ: Qaulity of Service and Future Directions, 1999.
[14] Mouchtaris, P. (Ed.). Voice over IP (VoIP) technology. Sponsor: SPIE,Conference Title: Voice Over IP (VoIP) Technology, 2001.
[15] H. Schulzrinne, S. Casner, R. Frederick, etc. Audio-Video Transport Working Group RFC 1889(RTP), January 1996.
[16] Markopoulou, Athina P.;Tobagi, Fouad A.;Karam, Mansour J. Assessment of VoIP quality over internet backbones. IEEE Infocom 2002, 2002.
[17] 汪亚光，汪敏．包头压缩技术在VOIP中的应用．上海大学学报，2001(1)，Vol．7．
[18] 黄永峰，周可，张江陵．IP电话系统中的消回声处理．数据采集与处理，2000(4)，Vol．15．
[19] ITU-T Telecommunication Standardization Sector, Recommendation H.323V2, Feb. 1998.
[20] ITU-T Telecommunication Standardization Sector, Recommendation H.245V3,June. 1996.
[21] ITU-T Telecommunication Standardization Sector, Recommendation H.225.0V3,May. 1996.
[22] 《因特网语音通信技术及其应用》黄永峰 编 人民邮电出版社．
[23] Liu, Xicheng; Li, Timothy J. Implementation of a prototype VoIP systems Journal of Computer Science and Technology, Sep 2000.
[24] Anquetil, Laurent Philippe;Bonnet, Gilles;Lapierre, Martine;Van Leekwijck,Werner;Willekens, Guido. New multimedia services using a server architecture. Alcatel Telecommunications Review, 2000.
[25] 云红艳，高岭，李祥生．远程访问系统中Radius的应用．西北大学学报，2000(3)，Vol．30．
[26] 《通信网的安全—理论与技术》王育民 刘建伟编著 西安电子科技大学出版社．
[27] http://www.justdn.org/justdn.v2/print.php?ID=193.
[28] Cisco公司《RADIUS Vendor-Specific Attributes Voice Implementation Guide》.http://www.cisco.com/univercd/cc/td/doc/product/access/acs serv/vapp dev/vsaig3.pdf.
[29] 侯艳，钟宝荣．VOIP电话系统的数据库系统的备份与恢复．计算机与现代化，2002(1)，Vol．77．
[30] Kos, Anton;Klepec, Borut;Tomazic, Saso. Techniques for performance improvement of VoIP applications. 11th IEEE Mediterranean Electronical Conference (Melecon 2002), 2002.
[31] M.Leech, M.Ganis, Y. Lee, etc. Network Working Group RFC 1928(SOCKS v5),March 1996.
[32] http://www.socks.permeo.com.