Hi All When using TCP socket, I loop send() or recv() until ALL the data has been transmitted (or error, disconnect, etc.), because TCP socket packet is transmitted in stream nature, maybe a byte, bytes or all bytes in one transfer. The UDP socket preserve message boundary which TCP socket doesn't. Does this means single call to sendto() will processed by single call recvfrom()?, and how about packet that exceeds UDP data MAX size?. So in code, do I need to loop sendto() or recvfrom() to transmit the data?. Example codes is: char packet[100]; size_t nbytes = 0; int ret; while (nbytes < sizeof(packet)) { ret = recvfrom(socket, packet + nbytes, addr, 0, sizeof(packet) - nbytes); if (ret <= 0) { /* deal with recvfrom() error */ } nbytes += ret } Thanks -- To unsubscribe from this list: send the line "unsubscribe linux-c-programming" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html