private void PingListener()
        {
            Thread.Sleep(TimeSpan.FromMinutes(1));
            while (true)
            {
                for (int i = _clients.Count; i >= 0; i++)
                {
                    Version v = new Version(0,0,0,0);
                    if (Version.TryParse(_clients[i].Version, out v))
                    {
                        if (v < new Version(2, 0, 5, 1))
                        {
                            //Client version does not support PING command!
                            continue;
                        }
                    }
                    else
                    {
                        //don't have the client version at all!
                        continue;
                    }

                    //fire off a message to the client, see what happens
                    try
                    {

                        byte[] buffer = _encoder.GetBytes("PING");
                        var stream = _clients[i].TClient.GetStream();
                        stream.Write(buffer, 0, buffer.Length);
                        stream.Flush();
                    }
                    catch (Exception e)
                    {
                        //this client doesn't appear to be connected anymore.  We should get rid of it
                        Logging.Write(e.Message);
                        Logging.Event(e.Message, EventLogEntryType.Error);
                        RemoveClient(_clients[i]);

                    }
                }

                Thread.Sleep(TimeSpan.FromMinutes(5));
            }
        }