receiving data from UDP socket

Ultimate purpose of the application is to receive UDP packets from a FPGA based development kit @ 16MB/sec.

Actual scenario is :
1. The development kit is sending UDP packets each containing 804 Bytes of data at a rate of 16MB/sec.
2. We are using recvfrom() function and putting the received data in Data_Out.txt file. Using size of the file created after a period of 50 sec , we concluded that the receiving speed is exactly same as that of transmission speed. (15 MB/sec)
3. We are capturing the packets simultaneously using wireshark also, for cross verification.
4. Initial 10 packets received by wireshark are found to be exactly same as that recvfrom() {inside the Data_Out.txt }
5. But as we go on checking, there are many places of mismatch between the two data sets.

So we are not able to find a reason behind this mismatch. If we were losing some packets it could have reduced the size of the Data_Out.txt considerably.(this is my opinion, as we are capturing data for around 50 secs, a considerable amount of time)

I fear we are doing some mishandling with the winsock API. So kindly have a look at the usage pasted below:

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CString TimeString1,TimeString2,TimeString3,TimeString4;
SOCKADDR_IN saddr;
sockaddr_in saddr1;
int length= sizeof(saddr1);
BYTE a0,a1,a2,a3;
CString addr;
Thread_Param->mDlg_Handle->m_remote_ip.GetAddress(a0,a1,a2,a3);
addr.Format(L"%u.%u.%u.%u",a0,a1,a2,a3);
char *addrchar= new char[addr.GetLength()+1];
wcstombs(addrchar,addr,addr.GetLength()+1);
saddr.sin_family=AF_INET;
saddr.sin_addr.s_addr=inet_addr(addrchar);
saddr.sin_port=htons(Thread_Param->mDlg_Handle->m_remote_udp_port);//temp_dlg->m_remote_udp_port

fd_set fds;
int n;
struct timeval tv;
FD_ZERO(&fds);
FD_SET(Thread_Param->mDlg_Handle->m_socket,&fds);
tv.tv_sec=0;
tv.tv_sec=110;
n=select(Thread_Param->mDlg_Handle->m_socket,&fds,NULL,NULL,&tv);

if(n==0)
{
AfxMessageBox(_T("TimeOut Set !!"));
}
else
{
AfxMessageBox(_T("Error !!"));

}
///////////////////////////////////////////////////////////////////////////////////////////////////////

int Total_recd=0;
int addrlen=sizeof(saddr);
int count=0;
char *Recv_Buff="";

int flag_fail;
#define TIME_OUT_LIMIT 40

int i=0;
while(i<400000)
{
recd=recvfrom(Thread_Param->mDlg_Handle->m_socket,RecvBuff1,804,0,(struct sockaddr *)&saddr, &addrlen);
if(recd!=804)
{
CString strMsg2;
strMsg2.Format(L"%d",recd);
if(recd!=-1)
{
AfxMessageBox(strMsg2+_T("Data not Received Properly !!!"),MB_ICONERROR);
}

}
else
{
count=count+recd;
i++;
fwrite(&RecvBuff1,1,recd,fp_out);
}


}

CString strmsg;
strmsg.Format(L"%d",count);
fclose(fp_out);
AfxMessageBox(strmsg+_T("Completed"));

-------------------------------------------------------------------------------------

hi sir
I am trying to point out my error after receiving packets by writing error codes in a switch statement.And I got an socket error i.e "WSAEWOULDBLOCK"(Resource Temporarily Unavailable)
But I don't know why this error happens please help me please..