IPP Mail Archive: RE: IPP> Notifications

RE: IPP> Notifications

Turner, Randy (rturner@sharplabs.com)
Wed, 4 Feb 1998 13:04:11 -0800

Its very likely that we come to the conclusion to poll; but there is
nothing that says we can't agree on an out-of-bound mechanism to IPP for
event notification, at least I don't think there's a reason. Also,
there's always IPP V2 and possibly another protocol mapping document.

Randy

-----Original Message-----
From: Paul Moore [SMTP:paulmo@microsoft.com]
Sent: Wednesday, February 04, 1998 12:07 PM
To: 'Carl Kugler'; ipp@pwg.org
Subject: RE: IPP> Notifications

No argument at all. This is othogonal to the XML debate.

I am looking at expanding IPP to cover many needs beyond the
relatively
simple feature set currently defined, the extensibility issue
led me to the
XML proposal, the unsolicited message issue led me to this
thread.

The point I am making is that using HTTP asymmetrically (i.e the
client
always POSTs, the printer always listens for POST - which is the
'natural'
use of HTTP) precludes the core IPP protocol from generating
asynchronous or
unsolicited reverse messages. This is a major limitiation - I
want to be
sure that everybody knows that we are doing it and that we all
accept the
trade-off. I'm sure we could invent lots of hacks later on the
will work
round this but that's not an ideal solution. What will actually
happen is
that we will all poll :-(

> -----Original Message-----
> From: Carl Kugler [SMTP:kugler@us.ibm.com]
> Sent: Wednesday, February 04, 1998 9:40 AM
> To: ipp@pwg.org
> Subject: Re: IPP> Notifications
>
> Paul-
>
> I would like to point out that the XML/new method proposal is
no better in
> this
> respect. The problem is not that IPP is asymmetric: the
underlying HTTP
> transport layer is asymmetric, and that is common to both
approaches.
>
> - Carl
>
>
>
> ipp-owner@pwg.org on 02/03/98 12:24:44 PM
> Please respond to ipp-owner@pwg.org @ internet
> To: ipp@pwg.org @ internet
> cc:
> Subject: IPP> Notifications
>
>
> Has anybody noticed that IPP will be useless for notifications
due to the
> asymmetry of the protocol? As currently constituted a printer
cannot send
> an
> unsolicted message to anybody.
>
> Was this discussed later on on the Thursday brainstorm?
>
>
>