主要通过对SIP协议的研究，根据这个协议的特点，设计出来一个基于SIP电话会议系统。用户可以通过WEB方式登录到预先建立好的会议室，进行电话会议。-primarily through the SIP, according to the characteristics of this agreement, designed a SIP-based telephone conferencing system. Web users can log on to advance ways to estab