It has now become the extensively – used session establishment protocol of VoIP and further been adopted to be the core protocol of session control for the Next Generation Network ( NGN ) due to its characteristic advantages of simplicity preferable expansibility and toilless realization .

它 固有 的 诸如简单性、良好的扩展性以及 比较 容易实现等优点已被下一代网络采用作为其核心呼叫控制协议，成为 当前使用最流行的VoIP会话建立协议。