关于winsock keepalive使用的几点疑问(基于TCP)

1、如果是服务端希望检测客户端的非正常掉线，KeepAlive属性是在服务端代码设置(连接建立成功之后)还是在客户端的代码设置呢？或者是两端都要设置？

2、关于结构体
struct tcp_keepalive {
u_long onoff;
u_long keepalivetime;
u_long keepaliveinterval;
};

不是非常明白keepalivetime和keepaliveinterval的含义，英文比较菜，MSDN的解释如下：
The keepalivetime member specifies the timeout, in milliseconds, with no activity until the first keep-alive packet is sent. The keepaliveinterval member specifies the interval, in milliseconds, between when successive keep-alive packets are sent if no acknowledgement is received.

可否认为是没经历keepaliveinterval时间，重新发送一次心跳包，一次成功的心跳包返回后，keepalivetime时间内不再发送心跳包？

3、对于完成端口而言，如果接收到成功的心跳包，GetQueuedCompletionStatus是否会返回呢？如果会返回的话，返回值为TRUE，lpNumberOfBytes 得到的值为0？ 如果心跳包确认超时的话，GetQueuedCompletionStatus会得到返回值FALSE？


不知道说清楚了没，希望大家能够帮我解惑一下，不胜感激！