IPP Mail Archive: Re: IPP>MOD Why use Job-Id instead of Job-URI for Jobs?

Re: IPP>MOD Why use Job-Id instead of Job-URI for Jobs?

Robert Herriot (Robert.Herriot@Eng.Sun.COM)
Tue, 9 Sep 1997 14:10:27 -0700

> From walker@dazel.com Tue Sep 9 13:53:49 1997
>
> > Can you give a few details? Do you maintain a mapping table? If so,
> > what triggers the removal of entries? Or do you use an extended attribute
> > in the print job to hold the mapping?
>
> Uhhh... I believe that I will leave it as an exercise for the user.
> Let's just say that there is a variety of ways that one might do it;
> certainly either of the solutions that you hint to above might work.
> I could even imagine one or two more.
>
> I do not mean to be too mysterious, but it seems sufficient to me
> that there are implementations in the field today that solve a
> similar problem.
>

I ask these questions because the two most obvious solutions that I cite
above have problems in the IPP context.

The gateway cannot use some extended attribute to store the LPD Job-Id in
because an IPP server would discard attributes it doesn't support.

The gateway has difficulty using a mapping table because the IPP
notification is weak (email only). A gateway would have to resort to
polling in order to determine what jobs can be removed from its mapping
table. This works, but its not a nice solution, and it doesn't scale
well.

I assume that DAZEL doesn't have these restrictions.

Bob Herriot