Publisher:

    void *context = zmq_ctx_new ();
    void *publisher = zmq_socket (context, ZMQ_PUB);
    int rc = zmq_bind(publisher, "epgm://en0;224.0.0.250:5555");

    int rcvval  = 20000000;
    int m = zmq_setsockopt(publisher, ZMQ_SNDBUF, &rcvval, sizeof rcvval);

    int optval = 100;
    m =  zmq_setsockopt(publisher, ZMQ_RATE, &optval, sizeof(optval));

    optval = 1;
    m =  zmq_setsockopt(publisher, ZMQ_RECOVERY_IVL, &optval, sizeof(optval));

    optval = 65000000;
    m =  zmq_setsockopt(publisher, ZMQ_SNDHWM, &optval, sizeof(optval));

    optval = 0;
    size_t opt_size = sizeof(optval);
    m = zmq_getsockopt(publisher, ZMQ_SNDBUF, &optval, &opt_size);

    char test[1000000];
    char* str = "aaaaabvbvbbvbvbvbvbvbvbvbbvbvbvbdvbhdvbdvhbdvhdbvhdbvhdbvhdbvdhvbdhvbdhvbdhvbdhvbdhvbdhvbdhhvbdhvbdh";
    for(int i = 0; i < 5000; i++)
    {
        strcat(test, str);
    }

    int sent_size = s_send(publisher, test);

Subscriber:

    void *context = zmq_ctx_new ();
    void *subscriber = zmq_socket (context, ZMQ_SUB);
    int rc = zmq_connect(subscriber, "epgm://en0;224.0.0.250:5555");
    assert (rc == 0);

    rc = zmq_setsockopt (subscriber, ZMQ_SUBSCRIBE,
                     "", 0);
    assert (rc == 0);

    int rcvval = 20000000;
    int m = zmq_setsockopt(subscriber, ZMQ_RCVBUF, &rcvval, sizeof rcvval);

    int optval = 65000000;
    m =  zmq_setsockopt(subscriber, ZMQ_RCVHWM, &optval, sizeof(optval));

    optval = 1;
    m =  zmq_setsockopt(subscriber, ZMQ_RECOVERY_IVL, &optval, sizeof(optval));

    optval = 100;
    m =  zmq_setsockopt(subscriber, ZMQ_RATE, &optval, sizeof(optval));

    char *bytesChar = s_recv(subscriber);