DSP send raw ethernet packets to PC than PC capturing these packets and send ack response. They are messaging MAC to MAC so there are no ip layer. I want to make real-time messaging in every 1ms. DSP send message every 1 milisecond but PC can not capture the messages and send reply under 1 milisecond. Capturing and sending packet takes 15 - 30 ms. This result too slow for me. How can I make this faster. I am using jpcap library and my operating system Win XP x32.
Capturing Code:
private void captor() {
try {
captor = JpcapCaptor.openDevice(cf.getDevice(), 100, true, 1);
} catch (Exception ex) {
Logger.getLogger(CapturingPacket.class.getName()).log(Level.SEVERE, null, ex);
}
}
private void capturing() {
Packet packet = captor.getPacket();
if (packet != null) {
if (packet.data.length > 0) {
EthernetPacket ethernetPacket = (EthernetPacket) packet.datalink;
String receivedDestMac = Common.byteToMacStringFormat(ethernetPacket.src_mac);
if (definedDestMac.equals(receivedDestMac)) {
captured(packet.data);
}
}
}
}
private class captureRunner implements Runnable {
public void run() {
captor();
while (running) {
capturing();
try {
Thread.sleep(0);
} catch (InterruptedException err) {
}
}
}
}
Sending Code:
private void send(byte[] message) {
try {
JpcapSender send = JpcapSender.openDevice(cf.getDevice());
Packet packet = new Packet();
//ethernet frame
EthernetPacket ethernetPacket = new EthernetPacket();
// #dst_mac
ethernetPacket.dst_mac = getDestMac();
// #src_mac
ethernetPacket.src_mac = cf.getDevice().mac_address;
// #frametype
ethernetPacket.frametype = Common.ETHERNET_FRAME_TYPE;
// #data
packet.data = message;
// datalink
packet.datalink = ethernetPacket;
send.sendPacket(packet);
send.close();
} catch (Exception ex) {
Common.showErrorMessage("Send Error");
Logger.getLogger(MessagingPacket.class.getName()).log(Level.SEVERE, null, ex);
}
}
"Capturing and sending packet takes 15 - 30 ms." -- This is normal. You cannot make this much faster. Windows is not a real-time operating system. Use a microcontroller instead (there are better options, like FPGA and ARM, but I have no experience with these).