PWG Draft Charter

This is a draft for the charter for the proposed Printer Working Group to be discussed in the PWG BOF at the San Jose IETF meeting on Dec 12th 1996. The proposal involves using HTTP and a lightweight version of ISO10175 Document Print Application.

PWG Charter 4.0

Internet Printing Project (ipp)

 Carl-Uno Manros 
Applications Area Director(s): 
 Keith Moore        
 Harald Alvestrand  
Area Advisor:

Mailing lists: 
 General Discussion:
 To Subscribe: 
  in body:        subscribe ipp

 Scott Isaacson 
Description of Working Group:

Internet printing involves using Internet technologies and services 
to find networked resources such as printers and share documents and 
then printing using those resources.  This working group will define 
a new application level distributed printing protocol as well as 
naming and service registration mechanisms.  The protocol can be used 
in a global, distributed environment where print service users 
(clients, applications, drivers, etc.) cooperate and interact with 
print service providers (servers, printers, gateways, etc.). Guiding 
principles for the working group include: 
-       platform independence, 
-       leverage existing technology,
-       support all types of output devices (not just printers),
-       keep it simple enough to embed in network attached printers,
-       hide printing complexity and implementation details, and
-       support all existing page description languages (including HTML).

There are several roles in which humans act with respect to a given 
printer.  These roles include:  User, Operator, and Administrator.  
For example, Users submit jobs and then manage their own jobs.  
Operators monitor printer status and control and manage all jobs at 
the printer.  Administrators create the printer instances and control 
the authorization of other Users and Operators.  The working group 
will generally limit its scope to include only User functionality, 
however, there may be a need to define some basic Operator 
functionality as well.

Users want to find and locate printers to which they are authorized 
to print. They want to search for printers using a standard Web 
browser.  They search for printers based on name, geographic 
location, and other device related capabilities and attributes.  
Users also need a way to limit the scope or context of their 
searches.  This includes support for searching for print devices both 
inside and outside their organizational fire walls.

NOTE: Throughout this document, the term browser specifically means 
an Internet Web Browser (HTML, HTTP, Netscape, Internet Explorer, 
Mosaic, etc.).  The term does not include MIB browsers or other 
browsers specific to a proprietary product or technology.

Once users find printers, they want to be able to 'install' the 
printer into the native, desktop operating system on which they are 
running.  This installation process includes installing any device 
specific components that are needed (e.g., the correct printer 
driver).  This allows printing from any application (e.g., 
spreadsheet, word processor, browser, etc.).  Users also want to 
print by reference.  This means that instead of submitting a print 
job that contains the entire document contents, a job can be 
submitted that contains only a reference to some existing document or 
set of documents.  This reference is resolved prior to actually 
printing the document(s).

Users want to set certain print job parameters at the time the job is 
submitted (e.g., number of copies, priority, job defaults, etc.).  
The underlying protocol must support job-to-printer capability 
matching.  This involves knowing both printer attributes and job 
attributes as well as having the ability to reason about 
relationships between the values of these attributes.  This is useful 
for rejecting print jobs that can not be printed (at submission time 
rather than at print time) as well as automatically locating a 
printer that is capable of printing a certain job.  Once a print job 
has been submitted and is being processed, users need to be able to 
cancel their own print jobs.

Users want to verify both the characteristics and status of both jobs 
and print devices by using a browser.  When checking the status of a 
device, users want to know how many jobs are being processed by the 
device as well as how many jobs are 'in front of' a given job.  Users 
also want to be able either to turn on or turn off job and device 
status reporting.  The working group will define a set of printing 
related events and also specify the notification methods that can be 

The working group shall leverage existing (and emerging) technologies 
for: authentication, authorization, privacy, and commercial 

The working group must define solutions that do not preclude the 
notion of multi-tiered configurations consisting of both logical and 
physical printers.  Also, the new job submission protocol must not 
preclude submitting jobs to any type of output device (e.g., fax, 
printer, gateway).  Also, the working group shall define 
extensibility paths so that similar extensions will interoperate and 
proprietary, dissimilar extensions will never conflict. The working 
group will not undertake defining a standard API set for Internet 
printing, but will support redirection from current print subsystems 
and interfaces as well as support direct programmatic implementations 
by vertical applications.

The working group shall encourage and solicit the input and 
participation from all printing related individuals and companies.  
For example, the working group will not only encourage participation 
by experts from printer vendors, but representatives from browsers, 
client desktop operating systems, network operating systems, Internet 
service providers, Page Description Languages (PDLs), and  commercial 
service bureaus.  Also, the working group shall coordinate its 
activities with other printing-related standards bodies.

The working group will not re-invent nor concern itself with the 
following issues:
 -       how operating systems 'temporarily' install printers
 -       command line tools and interfaces
 -       input devices such as scanners and fax-in
 -       nested HTML documents

This working group may define work that will replace RFC 1179 'Line 
Printer Daemon Protocol'  LPR/LPD was designed a long time ago with 
line printers in mind. It does not fit with current page oriented 
printing technologies.  Most printer vendors have made their own 
proprietary extensions which are mutually incompatible. The 
specifications out of this working group must enhance RFC 1179 in the 
following ways:
 -       Useful yet practical mechanisms for interoperability and 
 -       Support for the more complex, multiple content, multiple document, 
page oriented languages and printers of today
 -       Support for the new Internet and Web technologies of today

This effort will be developed and prototyped within a 6 month period 
since there has been considerable prior work done in this area. This 
prior body of work includes:

-       ISO/IEC 10175 Document Printing Application (DPA) parts 1 and 3.
-       POSIX System Administration - Part 4 (POSIX 1378.4) 
-       X/Open, 'A Printing System Interoperability Specification(PSIS)'
-       RFC 1759, Printer MIB

Goals and Milestones:

 Weekly teleconference - Wednesdays, starting November 13, 1997
 Mailing list - up and working
 November 22, 1996 - issue Internet-Draft document to IETF
 December 12, 1996 - attend BOF in IETF meeting in San Jose
 End December, 1996 or earlier - have IETF WG created
 April 1997 meeting of IETF - final polishing of specification
 April 1997 meeting of IETF - demo of prototype(s)
 May 1997 - First RFC(s) ready for publishing
 (further milestones between January - April 1997 to be added)


   No Current Internet-Drafts.

Request For Comments:

  RFC  Stat Published    Title 
------- -- ---------- -----------------------------------------
RFC1759 PS   Mar 95     Printer MIB