As long as each end-user may contact its trustworthy SIP proxy via a secure connection and authorize this proxy to encrypt the signaling data,the session information is secured end-to-end.

• 当每个终端用户能经由一条安全链接联系到它可信赖的SIP代理并授权该代理加密信号数据时,会话信息就得到了端到端的安全保护。