Poor multicast performance sending using boost::asio on Windows

Question

I have a very simple wrapper for boost::asio sockets sending multicast messages:

// header
class MulticastSender
{
public:

    /// Constructor
    /// @param ip - The multicast address to broadcast on
    /// @param port - The multicast port to broadcast on
    MulticastSender(const String& ip, const UInt16 port);

    /// Sends a multicast message
    /// @param msg - The message to send
    /// @param size - The size of the message (in bytes)
    /// @return number of bytes sent
    size_t send(const void* msg, const size_t size);

private:

    boost::asio::io_service m_service;
    boost::asio::ip::udp::endpoint m_endpoint;
    boost::asio::ip::udp::socket m_socket;

};

// implementation
inline MulticastSender::MulticastSender(const String& ip, const UInt16 port) :
    m_endpoint(boost::asio::ip::address_v4::from_string(ip), port),
    m_socket(m_service, m_endpoint.protocol())
{
    m_socket.set_option(boost::asio::socket_base::send_buffer_size(8 * 1024 * 1024));
    m_socket.set_option(boost::asio::socket_base::broadcast(true));
    m_socket.set_option(boost::asio::socket_base::reuse_address(true));
}

inline size_t MulticastSender::send(const void* msg, const size_t size)
{
    try
    {
        return m_socket.send_to(boost::asio::buffer(msg, size), m_endpoint);
    }
    catch (const std::exception& e)
    {
        setError(e.what());
    }
    return 0;
}

// read and send a message
MulticastSender sender(ip, port);
while(readFile(&msg)) sender.send(&msg, sizeof(msg));

When compiled on Windows 7 using Visual Studio 2013, I get throughput of ~11 MB/s, on Ubuntu 14.04 ~100 MB/s. I added timers and was able to validate the send(...) method is the culprit.

I tried with and without antivirus enabled, and tried disabling a few other services with no luck. Some I cannot disable due to permissions on the computer, like the firewall.

I assume there is a service on Windows running that is interfering, or my implementation is missing something that is effecting the application on Windows and not Linux.

Any ideas on what might be cauing this would be appreciated

Answer 1

Is windows and ubuntu running on the same machine?

If not, it seems that your windows machine is limited by 100Mbit Ethernet, while the ubuntu machine seems to work with 1Gbit Ethernet.

(In case thats not the cause of the problem, i am sorry for posting an anwser instead of commenting. But i am not able to do so and your code is that simple and the data rates are so obvious [11*8MB/s ~ 100Mbit/s and 100MB/s ~ 800Mbit/s]. I just had to make that hint...)