This paper is written based on the correlative technology of gripped in my work and the founding practical problem of IP telephone, and reading much VoIP technology and theory books.

• 本论文是基于我在实际工作中掌握的相关技术和发现的 IP 电话的实际问题，并阅读了大量关于 VoIP 的技术和理论的书籍写出。