Among them, signal adaptation and conversion is session foundation, the interworking between SIP and H.323 or ISUP is described, in which network framework, signal mapping and call flow are discussed in detail.

• 其中位于控制层面的信令协议适配与互通是会话的基础；论文选用两个比较有代表性的协议H.；323 和ISUP；从组网方式、信令消息映射以及呼叫流程等方面；分析了SIP 与它们的互操作。