WCF Web Socket Service Return 400 Bad Request Disconnected Status

Question

I'm trying to implement web socket service in my existing wcf solution.

To do this I create classes specified below:

[ServiceContract]
public interface IExampleWebSocketServiceCallback
{
    [OperationContract(IsOneWay = true, Action = "*")]
    Task SendMessageToClient(Message msg);
}

    [ServiceContract(CallbackContract = typeof(IExampleWebSocketServiceCallback))]
public interface IExampleWebSocketService
{
    [OperationContract(IsOneWay = true, Action = "*")]
    Task SendMessageToServer(Message msg);
}

public class ExampleWebSocketService : IExampleWebSocketService
{
    public async Task SendMessageToServer(Message msg)
    {
        var callback = OperationContext.Current.GetCallbackChannel<IExampleWebSocketServiceCallback>();
        if (msg.IsEmpty || ((IChannel)callback).State != CommunicationState.Opened)
        {
            return;
        }
        byte[] body = msg.GetBody<byte[]>();
        string msgTextFromClient = Encoding.UTF8.GetString(body);
        string msgTextToClient = string.Format(
            "Got message {0} at {1}",
            msgTextFromClient,
            DateTime.Now.ToLongTimeString());
        await callback.SendMessageToClient(
            CreateMessage(msgTextToClient));
    }
    private Message CreateMessage(string msgText)
    {
        Message msg = ByteStreamMessage.CreateMessage(
            new ArraySegment<byte>(Encoding.UTF8.GetBytes(msgText)));
        msg.Properties["WebSocketMessageProperty"] =
            new WebSocketMessageProperty
            { MessageType = WebSocketMessageType.Text };
        return msg;
    }
}

And here's key parts of my app configuration file for this service:

            <service behaviorConfiguration="ExampleWebSocketBehaviour" name="ExampleWebSocketService">
            <endpoint address="" binding="netHttpBinding" bindingConfiguration="textWSHttpBinding"
             contract="IExampleWebSocketService">
                <identity>
                    <dns value="localhost" />
                </identity>
            </endpoint>
            <host>
                <baseAddresses>
                    <add baseAddress="http://localhost:9896/ExampleWebSocketService/" />
                </baseAddresses>
            </host>
        </service>

            <behavior name="ExampleWebSocketBehaviour">
                <serviceMetadata httpGetEnabled="false" httpsGetEnabled="false"/>
                <serviceDebug includeExceptionDetailInFaults="false"/>
            </behavior>


        <netHttpBinding>
            <binding name="textWSHttpBinding" messageEncoding="Text" maxBufferPoolSize="9999999"
   maxReceivedMessageSize="9999999"
   maxBufferSize="9999999" >
                <webSocketSettings transportUsage="Always" createNotificationOnConnection="true"/>
            </binding>
        </netHttpBinding>

My existing solution not working properly - every time when i try to connect, I'm getting bad request response that i show in example below:

Could not connect to ws://localhost:9896/ExampleWebSocketService/

Error: Unexpected server response: 400
Handshake Details
Request URL: http://localhost:9896/ExampleWebSocketService/
Request Method: GET
Status Code: 400 Bad Request
Request Headers
Sec-WebSocket-Version: 13
Sec-WebSocket-Key: 12EXCkp1jWLWDwH4xOI5lg==
Connection: Upgrade
Upgrade: websocket
Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits
Host: localhost:9896
Response Headers
Transfer-Encoding: chunked
Server: Microsoft-HTTPAPI/2.0
soap-content-type: application/soap+xml; charset=utf-8

I can't find what cause this problem ? Is there is someting that I need to define also in app configuration to make it work ?