IPP Mail Archive: IPP> ADM - Minutes from PWG IPP phone conference, 3/25/98

IPP Mail Archive: IPP> ADM - Minutes from PWG IPP phone conference, 3/25/98

IPP> ADM - Minutes from PWG IPP phone conference, 3/25/98

Tom Hastings (hastings@cp10.es.xerox.com)
Wed, 25 Mar 1998 17:57:45 PST

<bigger>Minutes from PWG IPP Phone Conference 980325


Notes taken by Carl-Uno Manros and Tom Hastings.


Ron Bergman Dataproducts

Tom Hastings Xerox

Carl-Uno Manros Xerox

Ira Mcdonald High North

Randy Turner Sharp

Don Wright Lexmark

Jim Walker DAZEL

Peter Zehler Xerox

Harry Lewis IBM

Jay Martin Underscore


Carl-Uno Manros led the meeting. For today's agenda topics, he said

he would like to revisit the IPP notification and the host-to-device home

work assignments and DL discussions.

Status of IPP in the IESG and IPP LA Agenda:

Carl-Uno reported that contacts with Keith Moore make it clear that we

not see any feedback from him or the IESG in time for IETF41 next week,

and probably not before the PWG IPP meeting in Portland either. The

IETF41 IPP agenda is therefore limited to the discussion of IPP

notifications and mapping of directory attributes to SLP and LDAP.

Carl-Uno then made a quick review of other sessions in IETF41 that

might be of interest to IPP WG members coming to LA.


Then the discussion of IPP notifications started. Carl-Uno suggested

that we already have a number of inputs that could be used to work

out a solution for the simple kind of user notifications intended

in the IETF IPP work item. It was clear from the following discussion

that the PWG needs to view notifications in a wider scenario that

takes into account host-to-device, administrator etc. requirements,

but that this work could be done in parallel to developing a simple

notification solution for IPP 1.0. The notification specification is

expected to take the form of a standards track IETF RFC, which

specifies additional attributes to what is in the Model document.

Although the notification specification will be optional to

implement, we should aim for it to become a standards track document.

Discussions were held around how much flexibility the user needs to

have in specifying what should be returned in a notification. Some

suggested that standardized packages should be enough, but there

were also requirements to have full flexibility to specify the exact

attributes (including private attribute extensions) to be returned.

Unless the solution gets too complex, it looks like we should expect

a few standard packages to be specified and supported, but that

implementations could optionally support attribute level specification.

There was also discussion about the format of the notification.

Everybody seemed to agree that it should be in the form of a MIME

type, which is identical or very similar to the application/ipp

Mime type and should look more or less identical to the

List-Job-Attribute response format. There also seemed to be agreement

that the life cycle of a notification request is the same as for the

print job.

As part of this discussion, Tom Hastings introduced the DL draft on

how a directory attribute syntax could be defined. Bob Herriot and

Roger deBry had worked with Tom on this, but had not yet seen the

current version, when had been written by Tom. There was opposition from

Jim Walker and others about the parallel attribute value approach

taken in the proposal and Tom undertook to work out a full proposal

based on the original idea of introducing a new syntax for comparison.

Carl-Uno when summing up the discussion about notifications asked

for volunteers to write up a proposal based on the earlier text

in the model document, the current requirements document, Tom's

revised proposal for the directory attribute, and today's

discussion. Tom Hastings and Harry Lewis will try to have a draft

ready for discussion in Portland (April 8-9) with Jim Walker's review,

if there is time.

PWG Host-to-Device protocol discussion:

The next agenda item was the alternative approaches to arrive

at a suitable solution for a host-to-device protocol (which is

not intended as an IETF standard).

Don Wright introduced his PWG draft called "IPP to IEEE 1284.1

Mapping". This describes how IEEE 1284.1, a.k.a. TIP/SI, could be used

to transfer IPP attributes and document data from a print server

to a print device. A few minor extensions would be needed to

the IEEE TIP/SI standard itself to support the proposal. In addition,

the PWG would develop a PWG standard for a IPP Logical Unit (LU)

that works with TIP/SI that accepts IPP attributes directly.

Areas for further study would be internationalization and security,

plus an explicit mapping of TIP/SI to TCP/IP. Don wanted to have

further discussion of the document in the Portland IPP meeting

before investing more work in refining the draft.

Randy Turner then introduced his proposal on how to map IPP

directly on TCP/IP, which he claimed would solve most of the

problems that have been stated against using IPP as a

host-to-device protocol. The following discussion indicated

that people wanted the two channel approach that is used in

TIP/SI and CPAP (one for bi-directional control information

and one for data) to be added to Randy's proposal. Randy undertook

to have a revised version of the proposal ready for discussion in

Portland. It will introduce a second pull-only data channel

and rewrite some of the proposal for a new URI scheme.

Meeting adjourned at 12:30 PM.

There will not be any phone conferences for the next two weeks

due to the IETF41 and PWG IPP meetings. The next teleconference

will be held on April 15 at 10:00am PST.