A. trusted B. invited C. forced D. permitted

关于SIP中INVITE消息的描述中，正确的是A.由服务器发送B.用来邀请用户参加会话C.代理服务器自动用

As I had other______to fry yesterday, I was forced to decline Davids invitation to a dinne

I invited them _____ our house the next week. A. to call for B. to call at C. c

SIP请求消息，ACK的含义是（)A.请求再次发送INVITE消息B.对全部收到消息进行确认C.对INVITE以外

We are invited to a party _________in our club next Friday.A. to be held B. held C. be

SIP请求消息 ACK的含义是()A.请求再次发送INVITE消息B.对全部收到消息进行确认C.对INVITE以外