目 录一、可行性讨论的依据和范围1、 依据····························································12、 范围····························································2二、IP 电话的现状、标准、进展及问题·································22.1IP 电话的现状·····················································22.2IP 电话标准······················································32.3IP 电话的进展····················································62.4IP 电话存在的问题················································8三、建设 IP 电话网必要性与可行性····································93.1 建设 IP 电话网的必要性···········································93.2 建设 IP 电话网的可行性··········································103.3 简要结论·······················································11四、IP 电话网建设方案··············································114.1 总体方案························································114.2 实验网业务类型·················································134.3 网关及关守的设置方案···········································134.4 实验网网路组织·················································164.5 协议与信令·····················...