http通信类cinternetsession中OpenRequest第二个参数指定传输时间3秒//为什么无效?

一直传送；不知道何原因造成的command指令不对吗？
CString command;
command.Format("%s%d","/-wvhttp-01-/video.cgi?v=h264&duration",duration);
CInternetSession inet = CInternetSession(_T("SimpleH264DataExtract"));
CHttpConnection* pHttpCon = inet.GetHttpConnection(hostname,CHttpConnection::HTTP_VERB_GET
,80,NULL,NULL);
CHttpFile* pFile = pHttpCon->OpenRequest(CHttpConnection::HTTP_VERB_GET,
command,NULL,1,NULL,_T("HTTP/1.1"),NULL);

[解决办法]
3秒在何方？？？