Thread safe Parameters class (follow up)
I agree with the comments.  I don't see the advantage of your code over something more like below.  If there is a use case you have in mind, please clarify.

public class Parameters
{
    public int ConnectionTimeout {get; private set;} // or a readonly field if you prefer
    public int ResponseTimeout {get; private set;}

    public Parameters(int ct, int rt)
    {
        ConnectionTimeout = ct;
        ResponseTimeout = rt;
    }
}


Threading concerns often disappear when you can use immutable data structures.