Page 9: What is the length of the "Type" field (in this and the other message types)? Also: There is no explicit "version number" in the header anywhere, which makes me nervous. Is the "Reserved" field (which is present in all but the Cookie_Request) intended for this purpose? If so, perhaps it should be called "Version_Number" instead of "Reserved". If not, perhaps a "Version_Number" field should be added.