[Winpcap-users] about the sending packets rate...

[yulou liu]

 hi


I  have been working on a project in which PC send/receive  ethernet
frame to/from a FPGA board.
The connection via a 1 Gb switcher.

In order to test the limitation of the switcher,  I send a big file
(about 2.6GB) from PC TO PC via the switcher by an application like
IM. The rate is about 30 MB/s.

I programmed a software based on winpcap,  but the rate of sending
seems not so fast as what it is supposed to be.   The rate is about
4MB/S.

In order to figure out the bottleneck,  I made a simplest program
which only  sends Ethernet  frame in loop.  Each frame 's size is
about 1460 bytes.   And I captured the frame by Wireshark.  I  noticed
that the  period time between  each frames   is about 0.0002
seconds.    According to that , I can calculate the rate like :  1460
bytes/ 0.0002= 6.9 MB/S.   And I runed the program on PCs  with 100M
Ethernet cards  and  on 1G Ethernet cards. There is no difference no
matter that the netcard is  100M or  1G.

The question is how could I improve  Is there any parameters that I
need to configure  to improve the period time between the frames so
that I can increase the rate of sending Ethernet frame ?



void CWndDown::OnBtnTst()
{
// TODO: Add your control notification handler code here

//
int iAmount= sizeof (FrameHead ) + sizeof(FrameHead2 )+1440*sizeof
(char);//length of the frame
unsigned char *pData2=new unsigned char [iAmount ];//
FrameHead * pfHead=(FrameHead *)pData2; //
FrameHead2 * pfHead2=(FrameHead2 *)( pData2+sizeof (FrameHead ));//
unsigned char *pData=(unsigned char *)( pData2+sizeof (FrameHead ) +
sizeof(FrameHead2 ));//
CString tmp; //
unsigned char pp[6];//
unsigned long i;
//get the destination'S  MAC
for(i=0;i<6;i++)
       {
  tmp.Format("0x%c%c",m_MacAddrSel.macAddrFpgaA.GetAt(i*3),
        m_MacAddrSel.macAddrFpgaA.GetAt(i*3+1));
        pp[i]=_tcstoul(tmp,0,16);

       }

pfHead->DesAddr.addr0=pp[0];
    pfHead->DesAddr.addr1=pp[1];
    pfHead->DesAddr.addr2=pp[2];
    pfHead->DesAddr.addr3=pp[3];
    pfHead->DesAddr.addr4=pp[4];
    pfHead->DesAddr.addr5=pp[5];


//get the SOURCE'S MAC
for(i=0;i<6;i++)
       {
  tmp.Format("0x%c%c",m_MacAddrSel.macAddrPc.GetAt(i*3),
m_MacAddrSel.macAddrPc.GetAt(i*3+1));
        pp[i]=_tcstoul(tmp,0,16);//

       }


pfHead->SrcAddr.addr0=pp[0];
    pfHead->SrcAddr.addr1=pp[1];
    pfHead->SrcAddr.addr2=pp[2];
    pfHead->SrcAddr.addr3=pp[3];
    pfHead->SrcAddr.addr4=pp[4];
    pfHead->SrcAddr.addr5=pp[5];

pfHead->FrmLgth=htons(0x002e);//


pfHead->FrmTyp=htons(FRAME_DATA);


    pfHead2->len= 1;

memset(pData, 0x55, 1440);
pfHead2->seq=htonl(i);

int iLoopTime=1;

while(iLoopTime)
{
/* SEND PACKETS */
if (pcap_sendpacket(m_gadhandle,pData2, iAmount ) != 0)
{
MessageBox("\nError sending the packet: \n","提示",MB_OK|
MB_ICONINFORMATION);
}
}

delete []pData2;
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