some notes, mostly typed in before I read the draft:
- IPP notifications should not default to port 80. if you don't want to
use the same port as for IPP (and I can imagine instances where this
would cause problems) then you should allocate another port.
if you let the port be setable on notificaiton servers, and if you let
the requestor of the notification specify the URL to
which the notification should be sent, then the port assignment is
less of an issue - it can be specified in the URL using whatever
port will get through the various firewalls that might be in
the way (if there is such a port at all!) still, it would be better
to have a port number allocated for this purpose, even if the requestor
can specify a different port number, as this minimizes conflict.
- similarly, IPP notifications should not use http:. If you
use the IPP port I think ipp: would be okay. If you define a
completely new port a new prefix would be appropriate.
I'd like to avoid the situation where the default port
for URL type xyz: is different depending on what you're
using it for - let's keep a one-to-one correspondence between
URLs and default ports.
- Defining a new HTTP method is okay, and the HTTP crowd will be
happier about it than if you use POST again. But you're already
using POST for IPP, so I don't see any reason to insist that you define
a new method for IPP notifications.
does this answer the questions?