2.1.7 Internet Printing Protocol (ipp)

NOTE: This charter is a snapshot of the 48th IETF Meeting in Pittsburgh, Pennsylvania. It may now be out-of-date. Last Modified: 17-Jul-00

Chair(s):

Carl-Uno Manros <manros@cp10.es.xerox.com>

Applications Area Director(s):

Ned Freed <ned.freed@innosoft.com>
Patrik Faltstrom <paf@cisco.com>

Applications Area Advisor:

Ned Freed <ned.freed@innosoft.com>

Mailing Lists:

General Discussion:ipp@pwg.org
To Subscribe: ipp-request@pwg.org
Archive: ftp://ftp.pwg.org/pub/pwg/ipp/

Description of Working Group:

There is currently no universal standard for printing. Several protocols are in use, but each has limited applicability and none can be considered the prevalent one. This means that printer vendors have to implement and support a number of different protocols and protocol variants. There is a need to define a protocol which can cover the most common situations for printing on the Internet.

The goal of this working group is to develop requirements for Internet Printing and to describe a model and semantics for Internet Printing.

The further goal is to define a new application level Internet Printing Protocol for the following core functions:

- for a user to find out about a printer's capabilities - for a user to submit print jobs to a printer - for a user to find out the status of a printer or a print job - for a user to cancel a previously submitted job

The Internet Print Protocol is a client-server type protocol which should allow the server side to be either a separate print server or a printer with embedded networking capabilities. The focus of this effort is optimized for printers, but might be applied to other output devices. These are outside the scope of this working group.

The working group will also define a set of directory attributes that can be used to ease finding printers on the network.

The Internet Print Protocol will include mechanisms to ensure adequate security protection for materials to be printed, including at a minimum mechanisms for mutual authentication of client and server and mechanisms to protect the confidentiality of communications between client and server.

Finally, the IPP working group will produce recommendations for interoperation of LPR clients with IPP servers, and IPP clients with LPR servers. These recommendations will include instructions for both the translation of the LPR protocol onto IPP and the translation of the IPP protocol onto LPR. However, there is no expectation to provide new IPP features to LPR clients, nor is there an explicit requirement to translate LPR extensions to IPP, beyond those features available in the 4.2BSD UNIX implementation of LPR, and which are still useful today.

Other capabilities that will be examined for future versions include:

- security features for authentication, authorization, and policies - notifications from the server to the client - accounting

Subjects currently out of scope for this working group are:

- protection of intellectual property rights - fax input - scanning

The working group shall strive to coordinate its activities with other printing-related standards bodies, without the need to be strictly bound by their standards definitions. These groups are:

- ISO/IEC JTC 1/SC 18/WG 4 on Document Printing Application (ISO/IEC 10175 parts 1 - 3) - The Object Management Group (OMG) on OMG Printing Facility (in development) - IEEE (POSIX System Administration - Part 4: Printing Interfaces) - X/Open (Printing Systems Interoperabilty Specification) - The Printer Working Group

Goals and Milestones:

Mar 97

  

Submit Internet Printing Protoco/1.0: Model and Semantics as an Internet-Draft.

Mar 97

  

Submit Internet Printing Protoco/1.0: Protocol as an Internet-Draft.

Mar 97

  

Submit Internet Printing Protocol: Requirements and Scenarios as an Internet-Draft.

Mar 97

  

Submit Internet Printing Protoco/1.0: Directory Schema as an Internet-Draft.

Apr 97

  

Review of specification in IETF meeting in Memphis, TN, USA

May 97

  

Produce At least 2 implemented prototypes

Aug 97

  

Submit other Internet-Drafts to IESG for consideration as Proposed Standards.

Aug 97

  

Submit Internet Printing Protocol: Requirements and Scenarios I-D to IESG for publication as an Informational RFC.

Internet-Drafts:

Request For Comments:

RFC

Status

Title

 

RFC2565

E

Internet Printing Protocol/1.0: Encoding and Transport

RFC2566

E

Internet Printing Protocol/1.0: Model and Semantics

RFC2567

E

Design Goals for an Internet Printing Protocol

RFC2568

E

Rationale for the Structure of the Model and Protocol for the Internet Printing Protocol

RFC2569

E

Mapping between LPD and IPP Protocols

RFC2639

  

Internet Printing Protocol/1.0: Implementer's Guide

Current Meeting Report

Carl-Uno Manros, Chair, led the Internet Printing Protocol (IPP) WG session. Around 19 people attended.

Agenda:

Carl-Uno said that the IPP Extensions work was not formalized by IESG but the group has almost completed the work anyway. Ned Freed later indicated that he would prefer to pursue a modification to the existing IPP WG Charter rather than create a separate WG for these activities. However, he only supports this approach if there is general interest in the group to do so.

A timeline diagram showed that the first two IPP Bake-offs were held in 1998 and 1999. Current plan for Bake-off 3 is in October 2000, and expected IPP/1.1 Extensions Bake-off in 2001.

Finished Internet-Drafts:

Carl-Uno provided the list of Internet-Drafts on Notifications:

<draft-ietf-ipp-not-04.tx>

<draft-ietf-ipp-not-spec-04.txt>

<draft-ietf-ipp-job-prog-00.txt>

<draft-ietf-ipp-notify-mailto-02.txt>

<draft-ietf-ipp-indp-method-02.txt>

<draft-ietf-ipp-notify-poll-01.txt>

<draft-ietf-ipp-not-over-snmp-03.txt>

He noted that there is no MANDATORY Notification method according to the current Internet-Drafts. Both 'mailto' and 'indp' are described as methods that SHOULD be supported.

Bob Herriot provided slides that gave a "Quick Summary of Notifications". He briefly described the following items:

Bob gave more detail on each of the individual notification delivery methods, and a simple example of an IPP Notification.

He asked, "Should any of the Delivery Methods be REQUIRED? If so, which one(s)?"

Carl-Uno asked Ned Freed (Applications Area Director) his opinion on Bob's question. Ned was surprised that the Internet-Drafts were modified to SHOULD support. He asked what the objections were to making any method(s) MANDATORY.

Ned suggested a compromise: If you implement user notification, then you MUST do mailto. If you implement machine notification, then you MUST do indp. After further discussion, this did not seem to be an adequate conclusion. Ned then volunteered to discuss this issue further with the other Area Director and IESG members. He warned that his response on this topic might take a while. Several other WGs have recently submitted Internet-Drafts that will occupy his time in the near future.

Bob Herriot then asked a question about using HTTP Chunking with regard to notification messages. He asked the group whether HTTP proxies support chunking:

But none of the attendees could provide an answer. Ned suggested that Bob should forward the question to the HTTP reflector.

Carl-Uno listed a few other Internet-Drafts that the group has also been working on:

<draft-ietf-ipp-ops-set2-01.txt>

<draft-ietf-ipp-install-00.txt>

<draft-ietf-ipp-get-resource-00.txt>

<draft-ietf-ipp-ldap-printer-schema-02.txt>

Future Activity in 2000:

Carl-Uno gave some information about QualDocs:

Details on the 3rd IPP Bake-off:

IPP and Linux:

Meeting adjourned.

Slides

Agenda
Internet Printing Protocol (IPP)