C# check if port is open

Question

I'm looking for a piece of code that checks if a port if up. I know that there are other answered questions about this topic but they have a little issue. They are slow. If the port isn't open it freezes my app for about 5-6 seconds.

Code I found around ( and edited ):

public static bool IsServerOnline()
{
    try
    {
        using (var client = new TcpClient())
        {
            var result = client.BeginConnect(SIMPLE_CONFIG.IP, SIMPLE_CONFIG.PORT, null, null);
            // [declaration in SIMPLE_CONFIG.cs] SIMPLE_CONFIG.TIMEOUT = new Timespan(0,0,1); it should be 1 second
            var success = result.AsyncWaitHandle.WaitOne(new TimeSpan(0,0,SIMPLE_CONFIG.TIMEOUT));
            if (!success)
            {
                return false;
            }

            client.EndConnect(result);
        }

    }
    catch
    {
        return false;
    }
    return true;
}

If the port is up it instantly returns true but if not it freezes the app for a few seconds even though i set a timeout of 1 second ( which doesn't seem to be working )