Yes, I believe the Upgrade: method is also bi-directional, or so it would seem so far in my interpretation of the draft.
Carl Kugler wrote:
> > The SASL capability is bi-directional, it can allow either side to mandate
> > secure connections.
> Looks to me like HTTP-TLS-UPGRADE is also bi-directional. The client can initiate an upgrade to TLS by putting an "Upgrade:" header in the request, and/or the server can require the client to upgrade by returning a "418: Upgrade Required" error code in response to a request.
> See the original message at http://www.egroups.com/list/ipp/?start=4920