tex.GetPixels32();

void Start()
{
    webcamTexture = new WebCamTexture();
    Background.texture = webcamTexture;
    Background.material.mainTexture = webcamTexture;
    webcamTexture.Play();

    if (!_isStarted)
    {
        _isStarted = true;

        NetworkTransport.Init();
        m_Config = new ConnectionConfig();
        m_CommunicationChannel  = m_Config.AddChannel(QosType.ReliableFragmented);
        HostTopology topology = new HostTopology(m_Config, 12);
        m_GenericHostId = NetworkTransport.AddHost(topology, 0);
        byte error;
        m_ConnectionId = NetworkTransport.Connect(m_GenericHostId, ip, port, 0, out error);
    }
}

void Update()
{
    if (!_isStarted)
        return;

    NetworkEventType recData = NetworkTransport.Receive(out recHostId, out connectionId, out channelId, recBuffer, bufferSize, out dataSize, out error);

    switch (recData)
    {
        case NetworkEventType.Nothing:         //1
            break;
        case NetworkEventType.ConnectEvent:    //2
            Debug.Log("Received connection confirmation");
            _readyToSend = true;
            break;
        case NetworkEventType.DataEvent:       //3

            break;
        case NetworkEventType.DisconnectEvent: //4
            //one of the established connection has been disconnected
            Debug.Log(String.Format("Disconnect from host {0} connection {1}", recHostId, connectionId));

            break;
    }

    if (_readyToSend)
    {
        _readyToSend = false; // To send just the first frame

        byte[] colourArray = SerializeObject(MakeSerializable(GetRenderTexturePixels(webcamTexture))); // Serialize the webcam texture

        // Sending total size
        byte[] sizeToSend = BitConverter.GetBytes(colourArray.Length);
        NetworkTransport.Send(m_GenericHostId, m_ConnectionId, m_CommunicationChannel, sizeToSend, sizeToSend.Length, out error);

        byte[] bytes = new byte[bufferLenght];
        int remainingBytes = colourArray.Length;
        int index = 0;
        int i = 1;

        while (remainingBytes >= bufferLenght)
        {
            System.Buffer.BlockCopy(colourArray, index, bytes, 0, bufferLenght);
            NetworkTransport.Send(m_GenericHostId, m_ConnectionId, m_CommunicationChannel, bytes, bytes.Length, out error);
            remainingBytes -= bufferLenght;
            Debug.Log(i++ + "Remaining bytes: " + remainingBytes + " - Error: "+error);
            index += bufferLenght;
        }

        if (remainingBytes > 0) // Send the last fragment below bufferLenght bytes
        {
            System.Buffer.BlockCopy(colourArray, index, bytes, 0, remainingBytes);
            NetworkTransport.Send(m_GenericHostId, m_ConnectionId, m_CommunicationChannel, bytes, remainingBytes, out error);
            Debug.Log("Error: "+error);
        }
    }
}

void Start()
{
    if (!_isStarted)
    {
        _isStarted = true;

        NetworkTransport.Init();

        m_Config = new ConnectionConfig();

        m_CommunicationChannel  = m_Config.AddChannel(QosType.ReliableFragmented);

        HostTopology topology = new HostTopology(m_Config, 12);

        m_GenericHostId = NetworkTransport.AddHost(topology, port, null);
    }
}

void Update()
{
    if (!_isStarted)
        return;

    int recHostId;
    int connectionId;
    int channelId;
    byte[] recBuffer = new byte[bufferLenght];
    int bufferSize = bufferLenght;
    int dataSize;
    byte error;

    NetworkEventType recData = NetworkTransport.Receive(out recHostId, out connectionId, out channelId, recBuffer, bufferSize, out dataSize, out error);

    switch (recData)
    {
        case NetworkEventType.Nothing:         //1
            break;

        case NetworkEventType.ConnectEvent:    //2

                //somebody else connect to me
            Log.text += string.Format("Connect from host {0} connection {1}n", recHostId, connectionId);
            break;

        case NetworkEventType.DataEvent:       //3

            if (!sizeReceived)
            {
                sizeReceived = true;

                if (dataSize == 2)
                {
                    bytesToReceive = BitConverter.ToInt16(recBuffer, 0);
                }
                else if (dataSize == 4)
                {
                    bytesToReceive = BitConverter.ToInt32(recBuffer, 0);
                }

                Debug.Log("We will receive: "+bytesToReceive);
            }
            else
            {
                Log.text = string.Format("Received event host {0} connection {1} channel {2} message length {3}n", recHostId, connectionId, channelId, dataSize);

                Log.text += "Received " + bufferSize + " bytesn";
                bytesToReceive -= bufferSize;
                Log.text += "Remaining " + bytesToReceive + " bytesn";
            }
            break;

        case NetworkEventType.DisconnectEvent: //4

            break;

    }
}

no free events for long message
UnityEngine.Networking.NetworkTransport:Send(Int32, Int32, Int32, Byte[], Int32, Byte&)
CameraStreamer:Update() (at Assets/Scripts/Client/CameraStreamer.cs:112)