rtsp客户端请求数据问题

[ykmao10]

int main(int argc ,char **argv)
{
	if(argc < 2)
	{
		printf("the argv is not enough\n");
		return 0;
	}
	int cli_fd;
	struct sockaddr_in sevaddr;
	sevaddr.sin_family = AF_INET;
	sevaddr.sin_port = htons(8554);
	sevaddr.sin_addr.s_addr = inet_addr(argv[1]);
	//以上设置server地址信息
	cli_fd = socket(AF_INET,SOCK_STREAM,0);
	if(-1 == cli_fd)
	{
		printf("client socket set up fail,please check it\n");
		return 0;
	}
	int resault;
	resault = connect(cli_fd,(struct sockaddr*)(&sevaddr),sizeof(sevaddr));   //链接服务器
	if(-1 == resault)
	{
		printf("connect the server fail,please check it\n");
		return 0;
	}
	printf("connect server scucess\n");

	//rtsp服务器接受的命令数据
	char optionbuf[1000] = {"OPTIONS rtsp://192.168.1.104:8554/nxn.mp3 RTSP/1.0 \r\n \
		CSeq: 1 \r\n\r\n \
			User-Agent: live555 \r\n"};
	
	char describebuf[1000] = {"DESCRIBE rtsp://192.168.1.104:8854/nxn.mp3 RTSP/1.0 \r\n \
					CSeq: 2 \r\n \
					Accept: application/sdp \r\n\r\n \ 
					User-Agent: live555 \r\n"};
	char recvbuf[1000] = {0} ;
	/////////////////////////

	if(sendto(cli_fd,optionbuf,sizeof(optionbuf),0,NULL,NULL) == -1)
	{
		printf("send data to server has take error\n");
		return 0;
	}

	if(recvfrom(cli_fd,recvbuf,sizeof(recvbuf),0,NULL,NULL) == -1)
	{
		printf("recv data from server take error\n");
		return 0;
	}
	printf("%s\n",recvbuf);
	memset(recvbuf,0,1000);
	if(sendto(cli_fd,describebuf,sizeof(describebuf),0,NULL,NULL) == -1)
	{
		printf("send data to server has take error\n");
		return 0;
	}
	
	if(recvfrom(cli_fd,recvbuf,sizeof(recvbuf),0,NULL,NULL) == -1)
	{
		printf("recv data from server take error\n");
		return 0;
	}
	printf("%s\n",recvbuf);

	
	return 0;
}

代码如上，我现在的问题是为什么我第一次发送option命令的时候返回正确，然后我在发送describe命令的时候就出现服务器返回405的问题，我是过把describe命令放到第一次去发送就成功了，也就是说我这个代码第二次发送总是返回405，求大牛帮忙！！！

[ykmao10]

来大牛帮我看看啊