網路科技的進步帶動多媒體蓬勃發展，尤其以網際網路語音電話(VoIP)的應用更廣泛，如Skype與MSN受到大眾普遍使用與推廣。在網際網路語音電話系統中具有代表性的信令通訊協定，SIP目前已被各界廣泛使用。使用SIP的軟體與硬體裝置愈來愈多，每個網際網路電話都至少須配置一個IP位址才得以使用。現今的網際網路服務又以使用IPv4位址服務居多，然而IPv4位址於2011年耗竭殆盡，將不足以供給每一台網際網路語音電話裝置使用。所幸IPv6可提供大量的位址空間來解決IPv4位址不足的情況。雖然IPv6的佈署尚未普及且大眾使用多以IPv4位址為主，若貿然轉換至IPv6服務，勢必會造成網路上的衝擊。轉換的過渡時期中，IPv4與IPv6網路的共存可提供使用者或硬體裝置得以繼續獲得服務，並逐漸汰換IPv4的使用。IVI便可讓IPv4與IPv6網路兩端的使用者得以繼續運作溝通的轉換技術之一。但是IVI轉換技術並未對封包的承載資料進行轉換，於是我們針對使用SIP的網際網路電話，配合IVI轉換技術實作一SIP應用層閘道器，使得IPv4與IPv6 SIP封包得以轉換。

The progress of Internet technology brings the rapid growth of multimedia application, especially the application of Voice over Internet Protocol such as Skype and MSN which are popular in the world. One of the well-known signaling protocols of VoIP, Session Initiation Protocol (SIP), widely spreads and commonly applies. The software and devices in use of SIP gradually increase. Each VoIP device needs to assign an IPv4 address for communication. Nowadays the IPv4 addresses have been exhausted because it still widely uses IPv4 addresses for network. IPv6 which can provide large address space is proposed to replace IPv4. However the IPv6 deployment is not widespread. The duration of transition from both IPv4 and IPv6 networks can make users or devices in IPv4 and IPv6 networks communicate with each other. One of transition mechanism, the IVI translation mechanism, allows users to access IPv4 and IPv6 networks. But the IVI translation does not translate the payload of packet. We implement a translation for SIP in VoIP with IVI translation mechanism such that it can translate SIP messages form IPv4 or IPv6 networks.

[1] C. Bao, M. Chen, X. Li, J. Wu and H. Zhang, “The China Education and Research Network (CERNET) IVI Translation Design and Deployment for the IPv4/IPv6 Coexistence and Transition,” IETF RFC 6219, May 2011.
[2] T. Berners-Lee, R. Fielding, H. Frystyk, J. Gettys, P. Leach, J. Mogul and L. Masinter, “Hypertext Transfer Protocol – HTTP/1.1,” RFC 2616, June 1999.
[3] S. Casner, R. Frederick, V. Jacobson and H. Schulzrinne, “RTP: A Transport Protocol for Real-Time Applications,” IETF RFC 3550, July 2003.
[4] G. Camarillo, M. Handley, A. Johnston, J. Peterson, J. Rosenberg, H. Schulzrinne, R. Sparks and E. Schooler, “SIP: Session Initiation Protocol,” IETF RFC 3261, June 2002.
[5] C. Cunningham, S. Donovan, A. Johnston and K. Summers, “Session Initiation Protocol (SIP) Basic Call Flow Examples,” RFC 3665, December 2003.
[6] S. Deering and R. Hinden. “Internet Protocol, Version 6 (IPv6) Specification,” IETF RFC 2460, December 1998.
[7] R. Gilligan and E. Nordmakr, “Basic Transition Mechanisms for IPv6 Host and Routers,” IETF RFC 4213, October 2005.
[8] M. Handley, J. Rosenberg, H. Schulzrinne and E. Schooler, “SIP: Session Initiation Protocol,” IETF RFC 2543, March 1999.
[9] M. Handley, V. Jacobson and C. Perkins, “SDP: Session Description Protocol,” IETF RFC 4566, July 2006.
[10] M. Handley, C. Perkins and E. Whelan, “Session Announcement Protocol, ” IETF RFC 2974, October 2000.
[11] E. Nordmark, "Stateless IP/ICMP Translation Algorithm (SIIT)," RFC 2765, February 2000.
[12] Osip library http://www.gnu.org/software/osip/
[13] Kernel netlink http://www.kernel.org/doc/man-pages/online/pages/man7/rtnetlink.7.html
[14] PACKETH http://packeth.sourceforge.net/sourceforge/Home.html
[15] IVI http://www.ivi2.org/IVI/