求翻译：用户代理分为用户代理客户机和用户代理服务器，其中ＵＡＣ负责发起ＳＩＰ呼叫请求：ＵＡＳ负责对收到的ＳＩＰ呼叫请求作出应答，这里的应答内容包括对请求的接受、拒绝或重定向。是什么意思？

The user agent is divided into a user agent client and user agent server, which UAC is responsible for initiating a SIP call request: the UAS responsible for received SIP call request for a response, where the response includes the request, accept, reject, or redirect.

A user agent to the user agent client and user agent server, which is responsible for initiating UAC SIP call request: UAS SIP responsible for calls received on the request for a response, here are the answers to the request of the accept, reject, or redirect.

The user agent divides into the user agent client and the user agent server, in which UAC initiates the SIP call to request responsibly that,UAS is responsible to the SIP call which receives requested makes the reply, here reply content including accepts, the rejection or the heavy direction detecti

User agent into the user agent client and user agent server, UAC is responsible for initiating SIP call request: UAS is responsible for incoming SIP call response to requests, answering such requests to accept, reject or redirect.

正在翻译，请等待...