Building Security Gateway in SIP-based VoIP

• Main Authors: Jau-jan Tzeng, 曾昭展
• Other Authors: Jung-Shian Li
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/41185282999697407785

碩士 === 國立成功大學 === 電腦與通信工程研究所 === 97 === Recently, voice over IP becomes popular in today’s Internet. More and more devices could provide SIP-based VoIP, but most of them only support non-encrypted sessions. Some of the soft phones support the establishment of secure sessions, but they may not be compatible to other soft phones. Furthermore, most of the SIP hard phones do not support the setup of secured sessions. For setting up a secure session, both caller and callee should support the key exchange protocols, or the secure session could not be constructed. In this thesis, a secure architecture is proposed in the home/office networking environment. A special appliance, called Building Security Gateway (BSG), is designed to help weak SIP devices to perform security functions, such as initialization of secure sessions and encrypting/decrypting media similar to PCs. Furthermore, a prototype BSG is built in a home/office network, and BSG-based session mobility cases between UAs are constructed and the related protocol primitives are discussed. BSG could monitor the passing-by encrypted sessions and recover them into decrypted ones. The BSG architecture could help devices set up secure sessions and provide the monitoring functionality at the same time. CDR (call detail record) and recorded data stream could be kept in the BSG database.