NAT穿透法於SIP通訊協定之研究與實作

本論文乃針對網路電話協定SIP之重大缺失提出解決方案，最後並實作於嵌入式系統產品上，以達到理論與實務結合之目的。 SIP通訊協定之重大缺失起因於虛擬IP，由於現今IPv4之位址嚴重不足，再加上安全防火牆因素考量，採用虛擬IP用戶已超過75%以上，而通話雙方只要有一方位於虛擬IP，則SIP通訊協定會無法運作，雖然過去有許多專家提出如： UPnP，ALG，STUN，RTP-Relay....等方法，但均無法完全解決大型通訊系統之需求，因此本論文提出一先進之方法，稱之為NTIP(NAT Traversal using Intelligent Prediction)，此法可解決99%以上之虛擬IP，真正達到直接點對點(DP2P)互通之需求，實作結果證實NTIP方法之效能優於國際標準組織IETF所提出之STUN。本論文最後並將SIP通訊協定與NTIP方法實作於嵌入式產品上，此產品之作業系統MicroC/OS-II，系統小、成本低，因此本論文之理論與實務兼具，本論文所提出之方法優於國際標準組織IETF之STUN，而實作成果可即刻商品化。

關鍵字

SIP ； NAT ； NTIP ； Embedded

並列摘要

In this thesis, the advance method is proposed to improve the drawback of SIP protocol. Moreover, this advance method and SIP are implemented into the embedded product. In the real network, due to the lack of IP address in IPv4 mode and the security/firewall issue, more than 75% users are located under virtual IP address. If any one of two communicated parties locates under virtual IP, the SIP protocol will fail. In the past, many solutions were proposed to improve this drawback. However, the drawback is still existed. In this thesis, the NAT traversal method--NTIP is firstly proposed to improve the SIP protocol. More than 99% virtual IP are successfully employed with direct peer-to-peer(DP2P) mode. The performance of NTIP and DP2P mode are superior to the STUN of IETF in the experimental results. Moreover, the SIP protocol and NTIP method are implemented in the embedded VoIP gateway. The OS of this gateway is MicroC/OS-II. The performance and cost of this gateway are well enough for market.

並列關鍵字

SIP ； NAT ； NTIP ； Embedded

參考文獻

[4] Jonathan B. Postel,”Simple Mail Transfer Protocol ” ,RFC821,IETF,August 1982.

[7] P. Srisuresh and M. Holdrege,”IP Network Address Translator (NAT) Terminology and Considerations”, RFC2663, IETF, August 1999.

[12] 鍾耀興，SIP通訊協定於NAT網路環境之改良與實作，國立台北科技大學碩士論文，民國九十五年六月。

[1] M. Handley, and V. Jacobson, ”SDP:Session Description Protocol”, RFC2327, IETF, April 1998.

Google Scholar

[2] J. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, and E. Scholler,”SIP:Session Initiation Protocol”,RFC3261,IETF,June. 2002.