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Versions: (draft-wright-ipp-req) 00 01 02 03 RFC 2567

INTERNET DRAFT                 F.D. Wright, Lexmark International
<draft-ietf-ipp-req-03.txt>
November 16, 1998                           Expires: May 16, 1999


             Design Goals for an Internet Printing Protocol




STATUS OF THIS MEMO

This document is an Internet-Draft.  Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas, and
its working groups.  Note that other groups may also distribute working
documents as Internet-Drafts.

Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time.  It is inappropriate to use Internet-Drafts as reference material
or to cite them other than as ''work in progress.''

To learn the current status of any Internet-Draft, please check the
''1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow
Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe),
munnari.oz.au (Pacific Rim), ftp.ietf.org (US East Coast), or
ftp.isi.edu (US West Coast).

Abstract

This document is one of a set of documents, which together describe all
aspects of a new Internet Printing Protocol (IPP).  IPP is an
application level protocol that can be used for distributed printing
using Internet tools and technologies.  This document takes a broad look
at distributed printing functionality, and it enumerates real-life
scenarios that help to clarify the features that need to be included in
a printing protocol for the Internet.  It identifies requirements for
three types of users: end users, operators, and administrators.  The
design goals document calls out a subset of end user requirements that
are satisfied in IPP/1.0. Operator and administrator requirements are
out of scope for version 1.0.















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The full set of IPP documents includes:

Design Goals for an Internet Printing Protocol (this document)

Rationale for the Structure and Model and Protocol for the
    Internet Printing Protocol [IPP-RAT]
Internet Printing Protocol/1.0: Model and Semantics [IPP-MOD]
Internet Printing Protocol/1.0: Encoding and Transport [IPP-PRO]
Internet Printing Protocol/1.0: Implementer's Guide [IPP-IIG]

Mapping between LPD and IPP Protocols [IPP LPD]

The "Rationale for the Structure and Model and Protocol for the Internet
Printing Protocol" document describes IPP from a high level view,
defines a roadmap for the various documents that form the suite of IPP
specifications, and gives background and rationale for the IETF working
group's major decisions.

The "Internet Printing Protocol/1.0: Model and Semantics" document
describes a simplified model consisting of abstract objects, their
attributes, and their operations that is independent of encoding and
transport.  The model consists of a Printer and a Job object.  The Job
optionally supports multiple documents.  IPP 1.0 semantics allow end-
users and operators to query printer capabilities, submit print jobs,
inquire about the status of print jobs and printers, and cancel print
jobs.  This document also addresses security, internationalization, and
directory issues.

The "Internet Printing Protocol/1.0: Encoding and Transport" document is
a formal mapping of the abstract operations and attributes defined in
the model document onto HTTP/1.1.  It defines the encoding rules for a
new Internet media type called "application/ipp".

The "Internet Printing Protocol/1.0: Implementer's Guide" document gives
insight and advice to implementers of IPP clients and IPP objects.  It
is intended to help them understand IPP/1.0 and some of the
considerations that may assist them in the design of their client and/or
IPP object implementations.  For example, a typical order of processing
requests is given, including error checking.  Motivation for some of the
specification decisions is also included.

The "Mapping between LPD and IPP Protocols" document gives some advice
to implementers of gateways between IPP and LPD (Line Printer Daemon)
implementations.









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TABLE OF CONTENTS

1. INTRODUCTION.......................................................5
2. TERMINOLOGY........................................................5
3. DESIGN GOALS.......................................................7
 3.1. End-user.......................................................7
   3.1.1. Finding or locating a printer..............................7
   3.1.2. Create an instance of the printer..........................7
   3.1.3. Viewing the status and capabilities of a printer...........8
   3.1.4. Submitting a print job.....................................8
   3.1.5. Viewing the status of a submitted print job................9
   3.1.6. Canceling a Print Job.....................................10
 3.2. Operator (NOT REQUIRED FOR V1.0)..............................10
   3.2.1. Alerting..................................................10
   3.2.2. Changing Print and Job Status.............................10
 3.3. Administrator (NOT REQUIRED FOR v1.0).........................11
4. OBJECTIVES OF THE PROTOCOL........................................12
 4.1. SECURITY CONSIDERATIONS.......................................12
 4.2. Interaction with LPD (RFC1179)................................13
 4.3. Extensibility.................................................13
 4.4. Firewalls.....................................................14
 4.5. Internationalization..........................................14
5. IPP SCENARIOS.....................................................15
 5.1. Printer Discovery.............................................16
 5.2. Driver Installation...........................................17
 5.3. Submitting a Print Job........................................17
 5.4. Getting Status/Capabilities...................................18
 5.5. Asynchronous Notification.....................................19
 5.6. Job Canceling.................................................19
6. Security Considerations...........................................20
7. COPYRIGHT.........................................................21
8. REFERENCES........................................................22
9. ACKNOWLEDGMENTS...................................................23
10. AUTHOR'S ADDRESS.................................................23
11. APPENDIX - DETAILED SCENARIOS....................................24
 11.1. Printer discovery within an enterprise.......................24
 11.2. Printer discovery across enterprises.........................26
 11.3. Printer discovery on the Internet -logical operations........27
 11.4. Printer discovery on the Internet - authentication...........28
 11.5. Driver Download..............................................29
 11.6. Submitting a print job as a file.............................30
 11.7. Submitting a print job with two documents....................31
 11.8. Submitting a print job as a file, printing fails.............32
 11.9. Submitting a print job with authentication, PRIVACY and payment
  ...................................................................32
 11.10. Submitting a print job with decryption error................34
 11.11. Submitting a print job with authentication..................35
 11.12. Submitting a print job generated dynamically................36
 11.13. Submitting a print job with a Printer jam - CANCELED........37
 11.14. Submitting a print job with a Printer jam - recovered.......38
 11.15. Submitting a print job with server pull.....................39


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 11.16. Submitting a print job with referenced resources............40
 11.17. Getting Capabilities........................................41
   11.17.1. Submission Attributes...................................41
   11.17.2. Printer Capabilities....................................41
 11.18. Getting Status..............................................42
   11.18.1. Printer State/Status....................................42
   11.18.2. Job Status..............................................42
   11.18.3. Status of All My Jobs...................................42
 11.19. Asynchronous Notification...................................43
   11.19.1. Job Completion..........................................43
   11.19.2. Job Complete with Data..................................43
   11.19.3. Print Job Fails.........................................43
 11.20. Cancel a job................................................44
 11.21. End to end Scenario - within an enterprise..................45
 11.22. End to end Scenario - across enterprises....................47
 11.23. End to End Scenario - on the internet.......................50





































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1. INTRODUCTION


The IPP protocol is heavily influenced by the printing model introduced
in the Document Printing Application (DPA) [ISO10175] standard.
Although DPA specifies both end user and administrative features, IPP
version 1.0 (IPP/1.0) focuses only on end user functionality.

2. TERMINOLOGY


Internet Printing for the purposes of this document is the application
of Internet tools, programs, servers and networks to allow end-users to
print to a remote printer using, after initial setup or configuration,
the same methods, operations and paradigms as would be used for a
locally attached or a local area network attached printer.  This could
include the use of HTTP servers and browsers and other applications for
providing static, dynamic and interactive printer locating services,
user installation, selection, configuration, print job submission,
printer capability inquiry and status inquiry of remote printers and
jobs.

For the purposes of this document, a WEB Browser is software available
from a number of sources including but not limited to the following:
Microsoft Internet Explorer, NCSA Mosaic, Netscape Navigator, Sun Hot
Java!.  The major task of these products is to use the Hypertext
Transport Protocol (HTTP) to retrieve, interpret and display Hypertext
Markup Language (HTML).  These products are often a part of a complete
Internet Printing system because they are often used as a means of
obtaining the status of or more information about the printing system;
however, they may not be present in all implementations.

Throughout this document, 'printer' shall be interpreted to include any
device which is capable of marking on a piece of media using any
available technology.  These design goals do not include support for
multi-tiered printing solutions involving servers (single or multiple)
logically in front of the actual printing device yet all such
configurations shall be supported but shall appear to the end-user as
only a single device.

Throughout this document 'driver' refers to the code installed in some
client operating system to generate the print data stream for the
intended printer. Some computing environments may not include a separate
printer driver.  Rather, the generation of the proper print data stream
is accomplished in an application on that computer. How such a computer
environment or application is updated to support a new printer now made
available using IPP is outside the scope of IPP. The actual details for
installing a printer driver are operating system dependent and are also
outside the scope of IPP. See also section 4.1 (SECURITY CONSIDERATIONS)
for security implications of driver download and installation.

The IPP protocol will support the following physical configurations:


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- An IPP client talking to an IPP Printer object imbedded in a single,
  physical output device.
- An IPP Client talking to a server containing one or more IPP Printer
  objects. Each Printer object is associated with exactly one physical
  output device supported by the server. The protocol between the
  server and the output devices is undefined.
- An IPP Client talking to an IPP Printer object in a server. The
  Printer object is associated with one or more physical output
  devices, but the client only sees the Printer object, which is an
  abstraction and represents all of the associated physical output
  devices. The protocol between the server and the physical output
  devices is undefined.

Throughout this document, certain design goals will be identified as not
being a part of version 1.0 (or V1.0) of the protocol or as being
satisfied by means outside of IPP.  IPP is assumed to be one part, an
enabler, of a complete Internet Printing solution.  For example printer
instance creation is not performed by but is enabled by the protocol.
Globally, none of the operator or administrators wants and needs are
included in the design goals for version 1.0.  Some of the end-user
wants and needs may also be excluded from version 1.0 and will be so
noted in the description of them.  Subsequent versions of the protocol
(e.g. V2.0) may include support for these initially excluded wants and
needs.




























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3. DESIGN GOALS


The next three sections identify the design goals for an Internet
printing protocol from three roles assumed by humans: end-user,
operator, and administrator.  The goals defined here are only those that
need to be addressed by an Internet printing protocol.  Other wants and
needs, such as that the operator needs physical access to the printer
(e.g. to be able to load paper or clear jams) are not covered by this
document.  Section 5 contains scenarios which provide more detailed
examples of the entire process including discovery, status, printing and
end-of-job reporting.

3.1. END-USER


An end-user of a printer accepting jobs through the Internet is one of
the roles in which humans act.  The end-user is the person that will
submit a job to be printed on the printer.

The wants and needs of the end-user are broken down into six categories:
finding/locating a printer, creating a local instance of a printer,
viewing printer status, viewing printer capabilities, submitting a print
job, viewing print job status, altering the attributes of a print job.

3.1.1. Finding or locating a printer.


End-users want to be able to find and locate printers to which they are
authorized to print.  They want to be able to perform this function
using a standard WEB browser or other application.  Multiple criteria
can be applied to find the printers needed.  These criteria include but
are not limited to:

- by name (Printer 1, Joes-color-printer, etc.)
- by geographic location (bldg 1, Kentucky, etc.)
- by capability or attribute (color, duplex, legal paper, etc.)

Additionally, while it is outside of scope of IPP, end-users want to be
able to limit the scope of their searching to:

- inside a functional sub-domain
- include only a particular domain (lexmark.com)
- exclude specified domains

While an Internet printing protocol may not of itself include this
function, IPP must define and enable a directory schema which will
provide the necessary information for a directory service implementation
to consistently represent printers by their IPP attributes.

3.1.2. Create an instance of the printer.




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After finding the desired printer, an end-user needs to be able to
create a local instance of that printer within the end-user operating
system or desktop.  This local instance will vary depending upon the
printing paradigm of the operating system.  For example, some UNIX users
will only want a queue or a reference to a remote printer created on
their machine while other UNIX users and Windows NT users will want the
queue and also the necessary icons and registry entries to be created
and initialized.  Where required, drivers may need to be downloaded from
some repository and installed on the computer.  All necessary
decompressing, unpacking, and other installation actions should occur
without end-user interaction or intervention excepting initial approval
by the end-user.  Once the local instance of the printer has been
installed, it shall appear to the end-user of the operating system and
to the applications running there as any other printer (local, local
area network connected, or network operating system connected) on the
end-user desktop or environment.  IPP's role in this goal is simply to
enable the creation of the printer instance providing information such
as where to locate a printer driver for this printer, as an attribute of
an IPP Printer.

3.1.3. Viewing the status and capabilities of a printer.


Before using a selected printer or, in fact at any time, the end-user
needs the ability to verify the characteristics and status of both
printers and jobs queued for that printer.  When checking the
characteristics of a printer, the end-user typically wants to be able to
determine the capability of the device, e.g.:

- supported media, commonly paper, by size and type
- paper handling capability, e.g. duplex, collating, finishing
- color capability

When checking the status of the printer and its print jobs, the end-user
typically wants to be able to determine:

- is the printer on-line?
- what are the defaults to be used for printing?
- how many jobs are queued for the printer?
- how are job priorities assigned? (outside the scope of IPP)

3.1.4. Submitting a print job.


Once the desired printer has been located and installed, the end-user
wants to print to that printer from normal applications using standard
methods.  These normal applications include such programs as word
processors, spreadsheets, data-base applications, WEB browsers,
production printing applications, etc.  Additionally, the end-user may
want to print a file already existing on the end-user's computer --
"simple push."  In addition to printing from an application and simple
push, the end-user needs to have the ability to submit a print job by
reference.  Printing by reference is defined to mean as submitting a job


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by providing a reference to an existing document.  The reference, a URI,
will be resolved before the actual print process occurs.  Submitting a
job by reference relieves the user from downloading the document from
the remote server and then sending it via IPP to the printer.  This
saves both time and network bandwidth.

Some means shall be provided to determine if the format of a job matches
the capability of the printer.  This can be done by one of the following
(all of which are outside of scope of the IPP protocol):

     - the end-user selects the correct printer driver
     - the printer automatically selects the proper interpreter
     - the end-user uses some other manual procedure.

A standard action shall be defined should the job's requirements not
match the capabilities of the printer.

Because the end-user does not want to know the details of the underlying
printing process, the protocol must support job-to-printer capability
matching (all implementations are not necessarily required to implement
this function.)  This matching capability requires knowing both the
printer's capabilities and attributes and those capabilities and
attributes required by the job.  Actions taken when a print job requires
capabilities or attributes that are not available on the printer vary
and can include but are not limited to:

- rejecting the print job
- redirecting the print job to another printer (Not in V1.0)
- printing the job, accepting differences in the appearance

Print jobs will also be submitted by background or batch applications
without human intervention.

End-users need the ability to set certain print job parameters at the
time the job is submitted.  These parameters include but are not limited
to:

- number of copies
- single or two sided printing
- finishing
- job priority


3.1.5. Viewing the status of a submitted print job.


After a job has been submitted to a printer, the end-user needs a way to
view the status of that job (i.e. job waiting, job printing, job done)
and to determine where the job is in the print queue.

In addition to the need to inquire about the status of a print job,
automatic notification of the completion of that job is also required.


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Notification means are not defined by the protocol but the protocol must
provide a means of enabling and disabling the notification.

3.1.6. Canceling a Print Job


While a job is waiting to be printing or has been started but not yet
completed, the original creator/submitter of the print job (i.e. the
end-user) shall be able to cancel the job entirely (job is waiting) or
the remaining portion of it (job is printing.)  Altering the print job
itself is not a V1.0 design goal.



3.2. OPERATOR (NOT REQUIRED FOR V1.0)


An operator of a printer accepting jobs through the Internet is one of
the roles in which humans act.  The operator has the responsibility of
monitoring the status of the printer as well as managing and controlling
the jobs at the device.  These responsibilities include but are not
limited to the replenishing of supplies (ink, toner, paper, etc.), the
clearing of minor errors (paper jams, etc.) and the re-prioritization of
end-user jobs.  Operator wants and needs will not be addressed by V1.0
of the protocol.

The wants and needs of the operator include all those of the end-user
but may include additional privileges.  For example, an operator may be
able to view all print jobs on a printer while the end-user might only
be able to see his own jobs.

3.2.1. Alerting.


One of the required operator functions is having the ability to discover
or to be alerted to changes in the status of a printer particularly
those changes that cause a printer to stop printing and to be able to
correct those problems.  As such, an Internet printing protocol shall be
able to alert a designated operator or operators to these conditions
such as 'out of paper', 'out of ink', etc.  Additionally. the operator
shall be able to, asynchronous to other printer activity, inquire as to
a printer's or a job's status.

3.2.2. Changing Print and Job Status.


Another of the required operator functions is the ability to affect
changes to printer and job status remotely.  For example, the operator
will need to be able to re-prioritize or cancel any print jobs on a
printer to which the operator has authority.







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3.3. ADMINISTRATOR (NOT REQUIRED FOR V1.0)


An administrator of a printer accepting jobs through the Internet is one
of the roles in which humans act.  The administrator has the
responsibility of creating the printer instances and controlling the
authorization of other end-users and operators.  Administrator wants and
needs will not be addressed by V1.0 of the protocol.

The wants and needs of the administrator include all those of the end-
user and, in some environments, some or all of those of the operator.
Minimally, the administrator must also have the tools, programs,
utilities and supporting protocols available to be able to:

- create an instance of a printer
- create, edit and maintain the list of authorized end-users
- create, edit and maintain the list of authorized operators
- create, edit and maintain the list of authorized
   administrators
- create, customize, change or otherwise alter the manner in
   which the status capabilities and other information about printers
   and jobs are presented
- create, customize, or change other printer or job features
- administrate billing or other charge-back mechanisms
- create sets of defaults
- create sets of capabilities

The administrator must have the capability to perform all the above
tasks locally or remotely to the printer.
























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4. OBJECTIVES OF THE PROTOCOL


The protocol to be defined by an Internet printing working group will
address the wants and needs of the end-user (V1.0).  It will not, at
least initially, address the operator or administrator wants and needs
(V2.0).

The protocol defined shall be independent of the operating system of
both the client and the server.  Generally, any platform capable of
supporting a WEB Browser should be capable of being a client.
Generally, any platform providing a WEB/HTTP server and printing
services should be capable of being a server.  Usage of the WEB Browser
and Server is not required for IPP; the operating system, operating
system extensions or other applications may provide IPP functionality
directly.

In many environments such as Windows 95, Windows NT and OS/2, the print
data is created and transmitted to the printer on the fly rather than
being created, spooled and then transmitted to the printer (a typical
UNIX method.)  The Internet Printing Protocol must properly handle
either methodology and make this transparent to the end-user.


4.1. SECURITY CONSIDERATIONS

It is required that the Internet Printing Protocol be able to operate
within a secure environment. Wherever reasonable, IPP ought to make use
of existing security protocols and services. IPP will not invent new
security features when the design goals described in this document can
be met by existing protocols and services. Examples of such services
include Secure Socket Layer Version 3 (SSL3) [SSL] and HTTP Digest
Access Authentication [RFC2069].  Note: SSL3 is not on the IETF
standards track.

Since we cannot anticipate the security levels or the specific threats
that any given IPP print administrator may be concerned with, IPP must
be capable of operating with different security mechanisms and policies
as required by the individual installation. The initial security needs
of IPP are derived from two primary considerations. First, the printing
environments described in this document take into account that the
client, the Printer, and the document to be printed may each exist in
different security domains. When objects are in different security
domains the design goals for authentication and message protection may
be much stronger than when they are all in the same domain.

Secondly, the sensitivity and value of the content being printed will
vary from one instance of a print job to another. For example, a
publicly available document does not need the same level of protection
as a payroll document does.  Message protection design goals include
data origin authentication, privacy, integrity, and non-repudiation.


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In many environments (e.g. Windows, OS/2) a printer driver may be needed
to create the proper datastream for printer.  This document discusses
downloading such a new driver from a variety of sources.  Downloading
and installing any software, including drivers) on a computer exposes
that computer to a number of security risks including but not limited
to:

     - defective software
     - malicious software (e.g. Trojan horses)
     - inappropriate software (i.e. software doing something
          deemed unreasonable by the user.)

As such, proper security considerations and actions need to be taken by
the user and/or a system administrator to prevent the compromising of
the computer.  Administrators should configure downloading mechanism for
printer drivers in such a way as to be able to verify the source of
driver software and encrypt or otherwise protect that software during
download.

Examples including security considerations can be found in sections 5
(IPP SCENARIOS) and 11 (APPENDIX - DETAILED SCENARIOS) later in this
document.

4.2. INTERACTION WITH LPD (RFC1179)


Many versions of UNIX and in fact other operating systems provide a
means of printing as described in [RFC1179] (Line Printer Daemon
Protocol.)  This document describes the file formats for the control and
data files as well as the messages used by the protocol.  Because of the
simplistic approach taken by this protocol, many manufacturers have
include proprietary enhancements and extensions to 'lpd.'  Because of
this divergence and due to other design goals described in this
document, there is no requirement for backward compatibility or
interoperability with 'lpd'.  However, a mapping of LPD functionality
and IPP functionality shall be provided so as to enable a gateway
between LPD and IPP.


4.3. EXTENSIBILITY


The Internet Printing Protocol shall be extensible by several means that
facilitate interoperability and prevent implementation collisions:

     - by providing a process whereby implementers can submit proposals
     for registration of new attributes and new enumerated values for
     existing attributes.

          * that require review and approval.  The Internet Assigned
          Number Authority (IANA) will be the repository for such
          accepted registration proposals after review.


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          * that do not require review and approval.  IANA will be the
          repository for such registrations.

     - by providing syntax in the protocol so that implementers may add
     private (i.e. unregistered) attributes and  enumerated attribute
     values.

     - by providing versioning and negotiation so as to enable future
     implementations of IPP to interoperate with implementations of
     version 1.0 of IPP.


4.4. FIREWALLS


As stated in section 3 Design Goals, Internet printing shall, by
definition, support printing from one enterprise to another.  As such,
the Internet printing protocol must be capable of passing through
firewalls and/or proxy servers (where enabled by the firewall
administrator) preferably without modification to the existing firewall
technology.


4.5. INTERNATIONALIZATION


Users of Internet printing will come from all over the world.  As such,
where appropriate, internationalization and localization will be enabled
for the protocol.

























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5. IPP SCENARIOS


Each of the scenarios in this section describes a specific IPP
operation, such as submitting a print job. Section 11 contains several
detailed flows for each scenario to provide additional detail.  The
examples should not be considered exhaustive, but illustrative of the
functions and features required in the protocol.  Flows are intended to
be protocol neutral. It is not assumed that all of the functions and
features described in these scenarios will necessarily be supported
directly by IPP or in version 1.0 of IPP.

See the IPP Model and Semantics document for details on configurations
of clients, servers and firewalls.







































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5.1. PRINTER DISCOVERY


Client                                               Directory Service
Service

 +----------------------------------------------------------- >
    give me information on printers with these characteristics


 < -----------------------------------------------------------+
     Information on Printers matching these characteristics


The objective of printer discovery is to locate printers that meet the
client's wants and needs. The Directory Service should provide enough
information for the client to make an initial choice. The client may
have to connect to each individual Printer offered to get more detail.
Not all information available from the Directory Service is obtained
using IPP; some information may be administratively provided.

The actual protocol used between client and Directory or Name Service is
considered outside the scope of IPP. Printer Discover is included in the
scenarios to provide design goals for the directory schema for IPP
Printers and to further define Printer attributes.

Characteristics that might be considered when locating a Printer
include:

- capabilities of the Printer, e.g. PDLs supported
- physical location, e.g. in building 010
- driver required and location
- cost per page to print (outside the scope of IPP)
- whether or not printer is access controlled
- whether or not usage requires client authentication
- whether or not Printer can be authenticated
- whether or not payment is required for printing (outside the scope of
  IPP)
- maximum job size (spool size) (outside the scope of IPP)
- whether or not Printer support compression (outside the scope of IPP)
- whether or not Printer supports encryption
- administrative limits on this Printer
     - maximum number of copies per job
     - maximum number of pages per job

Responses could additionally include:

- how to get more information
     - web page
     - telephone number
     - help desk


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5.2. DRIVER INSTALLATION


Client                                               Printer

 +----------------------------------------------------------- >
    Where can I find a driver & software to install it?


 < -----------------------------------------------------------+
     URIs for drivers and install software


Driver here refers to the code installed in some client operating system
to generate the print data stream for the intended printer. The actual
details for installing a printer driver are operating system dependent
and are also outside the scope of IPP.  However, an IPP printer or a
directory service advertising an IPP Printer should be capable of
telling a client what drivers are available and /or required, where they
can be found, and provide pointers to installation instructions,
installation code or initialization strings required to install the
driver.  See section 4.1 (SECURITY CONSIDERATIONS) for security
implications of driver download and installation.


5.3. SUBMITTING A PRINT JOB


Client                                               IPP Printer

 +----------------------------------------------------------- >
    Here is a Print Job
     - Job attributes
     - Print data


 < -----------------------------------------------------------+
     Response

The protocol must support these sources of client data:

- Print data is a file submitted with the job
- Print data is generated on the fly by an application
- Print data is a file referenced by a URI

The protocol must handle overrun conditions in the printer and must
support overlapped printing and downloading of the file in devices that
are unable to spool files before printing them.





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Every print request will have a response. Responses will indicate
success or failure of the request and provide information on failures
when they occur. Responses would include things like:

- Got the print job and queued it
- Got the print job and am printing it
- Got the print job, started to print it, but printing failed
     - why it failed (e.g. unrecoverable PostScript error)
     - state of the printer
     - how much printed
- Got the print job but couldn't print it
     - why it can't be printed
     - state of the printer
- Got the print job but don't know what to do with it
- Didn't get a complete print job (e.g. communication failure)


5.4. GETTING STATUS/CAPABILITIES


Client                                               IPP Printer

 +----------------------------------------------------------- >
    Get status and/or capabilities of Printer


 < -----------------------------------------------------------+
     Status/Capabilities


Clients will need to get information about

- Static capabilities of the device
- Dynamic state of the Printer (e.g. out of paper)
- State of a specific job owned by this client
- State of all jobs owned by this client
     - queued
     - printing
     - completed
- Job submission attributes supported/required
     - scheduling attributes (e.g. priority)
     - production attributes (e.g. number of copies)












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5.5. ASYNCHRONOUS NOTIFICATION


Client                                               IPP Printer

 +----------------------------------------------------------- >
    Use the following method to notify me of Printer events

                              .
                              .
                              .
 < -----------------------------------------------------------+
     Asynchronous notification of Printer event


Clients must be able to request asynchronous notification for Printer
events such as

- job completion
- a fatal error that requires the job to be resubmitted
- a condition that severely impacts a queued job for this client
     e.g. printer is out of paper

Note: end-user notification is a V1.0 design goal while operator
notification is for V2.0.





5.6. JOB CANCELING


Client                                               IPP Printer

 +----------------------------------------------------------- >
    Cancel the named job as indicated


 < -----------------------------------------------------------+
     Response (did it or not)

Similarly clients must be able to make changes to jobs which have been
submitted and are queued for printing.  Changing of job attributes
should also be supported.  Job modifications, holding and releasing of
jobs are not included in the design goals for IPP v1.0.








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6. SECURITY CONSIDERATIONS


The security considerations for IPP are described in Section 4.1 above.

















































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7. COPYRIGHT


Copyright(C) The Internet Society 1997. All Rights Reserved.

This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it or
assist in its implementation may be prepared, copied, published and
distributed, in whole or in part, without restriction of any kind,
provided that the above copyright notice and this paragraph are included
on all such copies and derivative works.  However, this document itself
may not be modified in any way, such as by removing the copyright notice
or references to the Internet Society or other Internet organizations,
except as needed for the  purpose of developing Internet standards in
which case the procedures for copyrights defined in the Internet
Standards process must be followed, or as required to translate it into
languages other than English.

The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an "AS
IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK
FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT
LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT
INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE."


























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8. REFERENCES


[IPP-IIG]
  Hastings, T., Manros, C., "Internet Printing Protocol/1.0:
  Implementer's Guide", draft-ietf-ipp-implementers-guide-00.txt,
  November 1998, work in progress.

[IPP-LPD]
  Herriot, R., Hastings, T., Jacobs, N., Martin, J.,
  "Mapping between LPD and IPP Protocols",
  draft-ietf-ipp-lpd-ipp-map-05.txt, November 1998.

[IPP-MOD]
  deBry, R., Hastings, T., Herriot, R., Isaacson, S., Powell,
  P., "Internet Printing Protocol/1.0: Model and Semantics"
  draft-ietf-ipp-mod-11.txt, November, 1998.

[IPP-PRO]
  Herriot, R., Butler, S., Moore, P., Tuner, R.,
  "Internet Printing Protocol/1.0: Encoding and Transport",
  draft-ietf-ipp-pro-07.txt, November, 1998.

[IPP-RAT]
  Zilles, S., "Rationale for the Structure and Model and Protocol
   for the Internet Printing Protocol",
  draft-ietf-ipp-rat-04.txt, November, 1998.

[ISO10175]
  ISO/IEC 10175, Document Printing Application, June 1996.

[RFC1179]
  McLaughlin, L. III, (editor), "Line Printer Daemon Protocol"
  RFC 1179, August 1990.

[SSL]
Netscape, The SSL Protocol, Version 3, (Text version 3.02), November
1996.















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9. ACKNOWLEDGMENTS


This document draws heavily from preliminary work done by others
especially in the Printer Working Group (PWG).  The author gratefully
acknowledges the specific contributions of:

Scott Isaacson                   Roger deBry
Novell                           IBM
sisaacson@novell.com             rdebry@us.ibm.com

Carl-Uno Manros                  Robert Herriot
Xerox                            Sun
manros@cp10.es.xerox.com         Robert.Herriot@eng.sun.com

Tom Hastings                     Peter Zehler
Xerox                            Xerox
hastings@cp10.es.xerox.com       Peter.Zehler@usa.xerox.com



10. AUTHOR'S ADDRESS


F.D. (Don) Wright
Lexmark International
C14/035-3
740 New Circle Rd
Lexington, KY  40550

Phone: 606-232-4808
Fax: 606-232-6740
E-mail: don@lexmark.com





















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11. APPENDIX - DETAILED SCENARIOS


The following are more detailed scenarios illustrating how the Internet
Printing Protocol is expected to be used as a part of a complete
Internet Printing system.  Some parts of the scenarios include concepts,
functions and information that may be outside of the scope of version
1.0 of IPP (e.g. cost per page, payments means available, etc.)  The
information contained herein is meant to be generic.  There may not be
an exact wording or terminology match between these scenarios and the
implementation documents.


11.1. PRINTER DISCOVERY WITHIN AN ENTERPRISE


A user wants to find a color Postscript printer in his/her enterprise
which will print transparencies. The client, directory service, and
printer are all behind the same corporate firewall. Because color foils
are expensive, printers of this type are access controlled and require
an account to be established so that printing can be billed back to the
using department. Note the request to find a printer usable by Dept.
J15. Drivers for all supported printers are available from the server
they are associated with. A help desk is provided for end user support.
The printer is unattended.


Client                                  Directory Service

   +---------------------------------------------------------- >
     Find a printer with these characteristics
     - prints color, prints transparencies
     - prints Postscript
     - is in building 003
     - accessible by the client

   < ----------------------------------------------------------+
     Printer "Color-A"
     - prints color, prints transparencies
     - prints Postscript
     - in room H-6, building 003
     - driver ABC-Postscript-V1.3 required, here is URI
     - cost is $.45 per page for color transparencies
     - limit is 10 pages per job
     - authentication required to use printer
     - printer is unattended
     - help desk at x5001

      Printer "Color-B"
     - prints color, prints transparencies
     - prints Postscript
     - in room J-10, building 003


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     - driver XYZ-Postscript-V2.4 required, here is URI
     - cost is $1.25 page for color transparencies
     - limit is 5 pages per job
     - authentication is required to use printer
     - printer is unattended
     - help desk at x5001















































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11.2. PRINTER DISCOVERY ACROSS ENTERPRISES


A user in Company A wants to find a public printer in a business
partner's enterprise (Company B) on which to print a purchase order. The
client is behind one corporate firewall and the directory service and
the printer are behind a different corporate firewall. Drivers for all
supported printers are available from the server they are associated
with. A web page is provided for end user support for public printers.


Client                        Company B Directory Service

   +---------------------------------------------------------- >
     Find a printer with these characteristics
     - prints black and white
     - is in El Segundo, building A
     - is a public printer

   < ----------------------------------------------------------+
     Printer "Public-A"
     - prints black and white
     - prints Postscript
     - in El Segundo, room H-6, building A
     - driver ABC-Postscript-V1.3 required, here is URI
     - printer is public
     - help available at http://xerox/elSegundo/publicPrinters

      Printer "Public-B"
     - prints black and white
     - prints PCL/5e
     - is in El Segundo, room J-10, building A
     - driver XYZ-PCL-V2.4 required, here is URI
     - printer is public
     - help available at http://xerox/elSegundo/publicPrinters


















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11.3. PRINTER DISCOVERY ON THE INTERNET -LOGICAL OPERATIONS


A student wants to print a paper on a printer at his neighborhood Ink-
o's print shop. The report was written using Microsoft Word. The student
is interested in the cost of printing since his budget is limited. Note
the use of logical operators to find this information.

Client                          Ink-o's Directory Service

   +---------------------------------------------------------- >
     Find a Printer with these characteristics
     - prints color or black and white
     - costs less than $.50 per page
     - tell me about resolution and marking technology

   < ----------------------------------------------------------+
     Printer "Color-A"
     - prints color
     - 600 dpi laser printer
     - prints Postscript
     - driver ABC-Postscript-V1.3 required, here is URI
     - cost is $.50 per page for color
     - payment required prior to submitting print job
     - here is URI for more information on Ink-o's

      Printer "Mono-B"
     - prints black and white
     - 300 dpi inkjet printer
     - prints Postscript
     - driver XYZ-Postscript-V2.4 required, here is URI
     - cost is $0.35 page for black and white
     - payment required prior to submitting print job
     - here is URI for more information on Ink-o's


















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11.4. PRINTER DISCOVERY ON THE INTERNET - AUTHENTICATION


An executive in her hotel room is finishing an important presentation on
her laptop computer. She connects to a local print shop through the web
to get a copy of her charts printed for tomorrow's presentation. She
must find a print shop that is convenient to her hotel and can print
color transparencies. She wants to be sure that the printer can be
authenticated and can accept encrypted data.



Client                         SirZippy Directory Service

   +---------------------------------------------------------- >
     Find a Printer with these characteristics
     - prints color transparencies
     - is in Boulder, Colorado
     - Printer can be authenticated
     - Printer supports encryption


     Tell me when you are open for business

   < ----------------------------------------------------------+
     Printer "Color-A"
     - prints color transparencies
     - prints Postscript
     - driver ABC-Postscript-V1.3 required, here is URI
     - payment required prior to submitting print job
     - Printer can be authenticated
     - Data can be encrypted
     - Located at 1670 Pearl Street, Boulder, CO
     - This Branch is open 24 hours a day


     Printer "Color-B"
     - prints color transparencies
     - prints Postscript
     - driver ABC-Postscript-V1.3 required, here is URI
     - payment required prior to submitting print job
     - Printer can be authenticated
     - Data can be encrypted
     - Located at 1220 Arapahoe, Boulder, CO
     - This Branch is open from 9:00 am to 6:30 pm







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11.5. DRIVER DOWNLOAD


An end user in an enterprise wants to print a lengthy report on a newly
installed high speed PostScript printer. Since she will likely use this
printer often, she would like to download a driver and install it on her
workstation. She is running Windows 95.  Note:  Driver download is not a
V1.0 design goal.


Client                                        IPP Printer

   +---------------------------------------------------------- >
     Tell me where to find print drivers for you



   < ----------------------------------------------------------+
     Driver install file is at
     http://www.ibm.com/drivers/NP12a/Win95
































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11.6. SUBMITTING A PRINT JOB AS A FILE


An end-user wants to submit a print job. The print file already exists
on his workstation. The client and printer are behind the same corporate
firewall. The printer is available to anyone behind the firewall and no
authorization or authentication is required. The data is pushed to the
printer. The printer is capable of spooling the output. No errors occur.

Client                                        IPP Printer

   +---------------------------------------------------------- >
     Here is a print job
     - job name = MyJob
     - notify me by email when done printing
     - print on iso-a4-white paper
     - print on both sides of the paper
     - return status of the printer in response
     - document is in Postscript format
     - here is the document to print

   < ----------------------------------------------------------+
     Print job accepted and spooled
     - job id = #12345
     - current state of print job = spooled
     - submission time = 02/12/97, 15:35
     - printer state = printing

























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11.7. SUBMITTING A PRINT JOB WITH TWO DOCUMENTS


An end-user wants to submit a print job. The print file already exists
on his workstation. The client and printer are behind the same corporate
firewall. The printer is available to anyone behind the firewall and no
authorization or authentication is required. The data is pushed to the
printer. The job consists of two separate documents. The printer is
capable of spooling the output. No errors occur.

Client                                        IPP Printer

   +---------------------------------------------------------- >
     Here is a print job
     - job name = MyJob
     - notify me by email when done printing
     - print on iso-a4-white paper
     - print on both sides of the paper
     - return status of the printer in response

   < ----------------------------------------------------------+
     Print job accepted and spooled
     - job id = #12345
     - submission time = 02/12/97, 15:35
   +---------------------------------------------------------- >
     - here is the document to print

   < ----------------------------------------------------------+
     - OK

   +---------------------------------------------------------- >
     - here is the document to print, it is the last document.

   < ----------------------------------------------------------+
     - OK


















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11.8. SUBMITTING A PRINT JOB AS A FILE, PRINTING FAILS


An end-user wants to submit a print job. The print file already exists
on his workstation. The client and printer are behind the same corporate
firewall. The printer is available to anyone behind the firewall and no
authorization or authentication is required. The data is pushed to the
printer. The printer is not capable of spooling the output so it begins
printing while still receiving the file. An error occurs and the printer
cannot complete printing (in this case the user requires A4 paper and
that paper size is not available on the printer.)

Client                                        IPP Printer

   +---------------------------------------------------------- >
     Here is a print job
     - job name = MyJob
     - notify me by email when done printing
     - print on iso-a4-white paper
     - print on both sides of the paper
     - return status of the printer in response
     - document is in Postscript format
     - here is the document to print

   < ----------------------------------------------------------+
          Print job accepted

     - printing failed
     - current state of print job = canceled (A4 not available)
     - submission time = 02/12/97, 15:35
     - printer state = ready

11.9. SUBMITTING A PRINT JOB WITH AUTHENTICATION, PRIVACY AND PAYMENT


A traveling executive needs to print a set of transparencies for an
important business meeting. The charts are in Lotus Freelance format on
his notebook computer. He has located a SirZippy print shop near his
hotel that will print color transparencies. Because the information on
the charts is sensitive, he wants to be sure that his data is sent to
the Printer in an encrypted format. He also wants to authenticate the
Printer. The Printer also authenticates the user. Payment occurs across
the Internet.


Client                                               IPP Printer

   +---------------------------------------------------------- >
   < ----------------------------------------------------------+

     Mutual authentication and exchange of secret keys



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   +---------------------------------------------------------- >
     Here is a print job (encrypted)
     - job name = MyJob
     - notify me by email when done printing
     - print on iso-a4-white paper
     - print on both sides of the paper
     - return status of the printer in response
     - tell me where to pick up output
     - document is in Postscript format
     - here is the document to print

   < ----------------------------------------------------------+
     Print job accepted and spooled (encrypted)
     - job id = #12345
     - current state of print job = spooled
     - submission time = 02/12/97, 15:35
     - printer state = printing
     - payment required to proceed with job
     - pick up at 230 East Main after 3:30 pm today

   +---------------------------------------------------------- >
   < ----------------------------------------------------------+
     Payment transaction






























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11.10. SUBMITTING A PRINT JOB WITH DECRYPTION ERROR


A traveling executive needs to print a set of transparencies for an
important business meeting. The charts are in Lotus Freelance format on
his notebook computer. He has located a SirZippy print shop near his
hotel that will print color transparencies. Because the information on
the charts is sensitive, he wants to be sure that his data is sent to
the printer in an encrypted format. He also wants to authenticate the
printer. The printer also authenticates the user. Payment occurs across
the Internet. An error occurs during decryption.


Client                                        IPP Printer

   +---------------------------------------------------------- >
   < ----------------------------------------------------------+
     Mutual authentication and exchange of secret keys


   +---------------------------------------------------------- >
     Here is a print job (encrypted)
     - job name = MyJob
     - notify me by email when done printing
     - print on iso-a4-white paper
     - print on both sides of the paper
     - return status of the printer in response
     - tell me where to pick up output
     - document is in Postscript format
     - here is the document to print

   < ----------------------------------------------------------+
     Print job accepted and spooled (encrypted)
     - job id = #12345
     - current state of print job = spooled
     - submission time = 02/12/97, 15:35
     - printer state = printing
     - payment required to proceed with job
     - pick up at 230 East Main after 3:30 pm today

   +---------------------------------------------------------- >
   < ----------------------------------------------------------+
     Payment transaction
     .
     .
     .
   < ----------------------------------------------------------+
     Asynchronous response (email in this case)
     - decryption failed on job #12345
     - no pages printed
     - current state of job = aborted


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11.11. SUBMITTING A PRINT JOB WITH AUTHENTICATION


An end-user wants to submit a print job. The print file already exists
on his workstation. The client and printer are behind the same corporate
firewall. The printer is available to anyone behind the firewall but
authentication and authorization is required. Authorization takes place
using the authenticated end-user's name. The data is pushed to the
printer. The printer is capable of spooling the output.


Client                                        IPP Printer

   +---------------------------------------------------------- >
   < ----------------------------------------------------------+
     Authentication

     Note: An authentication failure would end the transaction at
               this point.

   +---------------------------------------------------------- >
     Here is a print job
     - job name = MyJob
     - notify me by email when done printing
     - print on iso-a4-white paper
     - print on both sides of the paper
     - return status of the printer in response
     - tell me where to pick up output
     - document is in Postscript format
     - here is the document to print

   < ----------------------------------------------------------+
     Print job accepted and spooled
     - job id = #12345
     - current state of print job = spooled
     - submission time = 02/12/97, 15:35
     - printer state = printing
















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11.12. SUBMITTING A PRINT JOB GENERATED DYNAMICALLY


An end-user wants to submit a print job. The print data is generated
dynamically and is being transmitted by a printer driver on the client
workstation as available. The client and printer are behind the same
corporate firewall. The printer is available to anyone behind the
firewall and no authentication and authorization is required. The data
is pushed to the printer. The printer is capable of spooling the output.
No error occurs.


Client                                        IPP Printer

   +---------------------------------------------------------- >
     Here is a print job
     - job name = MyJob
     - notify me by email when done printing
     - print on iso-a4-white paper
     - print on both sides of the paper
     - return status of the printer in response
     - document is in Postscript format
     - here is the print job


   < ----------------------------------------------------------+
     Print data accepted and spooling started
     - job id = #12345
     - current job state = spooled
     - submission time = 02/12/97, 15:35
     - printer state = printing






















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11.13. SUBMITTING A PRINT JOB WITH A PRINTER JAM - CANCELED


An end-user wants to submit a print job. The print data is generated
dynamically and is being transmitted by a printer driver on the client
workstation as available. The client and printer are behind the same
corporate firewall. The printer is available to anyone behind the
firewall and no authentication and authorization is required. The data
is pushed to the printer. The printer is not capable of spooling the
output. The printer jams notifies the user and the user chooses to
cancel the job.


Client                                            IPP Printer
   +---------------------------------------------------------- >
     Here is a print job
     - job name = MyJob
     - notify me by email when done printing
     - print on iso-a4-white paper
     - print on both sides of the paper
     - return status of the printer in response
     - document is in Postscript format
     - here is the document to print

   < ----------------------------------------------------------+
     Print data accepted and printing started
     - job id = #12345

   +---------------------------------------------------------- >
     - What is the status of print job #12345?

   < --------------------------------------------------------- +
     - Job #12345 accepted but printer jammed, cannot continue

   +---------------------------------------------------------- >
     - Cancel job #12345

   * Printer flushes remaining data
   < ----------------------------------------------------------+
      Print job terminated
     - current job state = canceled
     - submission time = 02/12/97, 15:35
     - printer state = jammed










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11.14. SUBMITTING A PRINT JOB WITH A PRINTER JAM - RECOVERED


An end-user wants to submit a print job. The print data is generated
dynamically and is being transmitted by a printer driver on the client
workstation as available. The client and printer are behind the same
corporate firewall. The printer is available to anyone behind the
firewall and no authentication and authorization is required. The data
is pushed to the printer. The printer is not capable of spooling the
output. The printer jams, notifies the user and the user clears the jam
and elects to continue.


Client                                        IPP Printer

   +---------------------------------------------------------- >
     Here is a print job
     - job name = MyJob
     - notify me by email when done printing
     - print on iso-a4-white paper
     - print on both sides of the paper
     - return status of the printer in response
     - document is in Postscript format
     - here is the document to print

   < ----------------------------------------------------------+
     Print data accepted and printing started
     - job id = #12345

   < --------------------------------------------------------- +
     - Notification: printer jammed, cannot continue

   * Jam is clear by human intervention, printing continues

   +---------------------------------------------------------- >
      Here is the last part of the document to print

   < ----------------------------------------------------------+
      Print job received
     - current job state = printing
     - submission time = 02/12/97, 15:35
     - printer state = printing











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11.15. SUBMITTING A PRINT JOB WITH SERVER PULL


An end-user wants to submit a print job. The print data is in a file and
is publicly available. It is pulled by the printer. The client and
printer are behind the same corporate firewall. The printer is available
to anyone behind the firewall and no authentication and authorization is
required. The printer is capable of spooling the output. Printing may
start before the entire job has been pulled.

Client                                        IPP Printer

   +---------------------------------------------------------- >
     Here is a print job
     - job name = MyJob
     - notify me by email when done printing
     - print on iso-a4-white paper
     - print on both sides of the paper
     - return status of the printer in response
     - here is a reference to the data to be printed

   < ----------------------------------------------------------+
     Print data accepted and printing started
     - job id = #12345
     - current state of job = spooled
     - submission time = 02/12/97, 13:15
     - printer state = printing

     .
     .
    < ----------------------------------------------------------+
     Get the file to be printed

    +---------------------------------------------------------- >
     Here it is

     Note: Failure to find the file, would end the transaction
               with an error at this point and an asynchronous
               notification would be send to the Client.

    < ----------------------------------------------------------+
      Data received











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11.16. SUBMITTING A PRINT JOB WITH REFERENCED RESOURCES


An end-user wants to submit a print job.  Part of the print data is on a
file on the user's workstation. It is pushed by the client, but the
print job requires some resource not included in the print file. The
client and printer are behind the same corporate firewall. The printer
is available to anyone behind the firewall and no authentication and
authorization is required. The printer is capable of spooling the
output. No errors occur.


Client                                        IPP Printer

   +---------------------------------------------------------- >
     Here is a print job
     - job name = MyJob
     - notify me by email when done printing
     - print on iso-a4-white paper
     - print on both sides of the paper
     - return status of the printer in response

   < ----------------------------------------------------------+
     Print job accepted and spooled
     - job id = #12345
     - submission time = 02/12/97, 15:35

   +---------------------------------------------------------- >
     - here is the document to print

   < ----------------------------------------------------------+
     - OK

   +---------------------------------------------------------- >
     - here is the URI to print, it is the last document.

   < ----------------------------------------------------------+
     - OK

    < ----------------------------------------------------------+
      Get the external resource

    +---------------------------------------------------------- >
      Here it is









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11.17. GETTING CAPABILITIES
11.17.1. Submission Attributes


An end-user wants to get the production and scheduling attributes that
are supported or required when submitting jobs to this printer. The
client will use these attributes when forming the subsequent print
request.

Client                                        IPP Printer
   +---------------------------------------------------------- >
     I'm going to submit a Postscript job
     give me your job submission attributes

   < ----------------------------------------------------------+
     Postscript production attributes for this Printer are:
     - medium-select = us-letter-white, us-legal-white
        - default is us-letter-white
        -   copies = 1,2,3,4,5
        - default is 1
             - print-quality = draft, normal, high
        - default is draft
             - sides = 1-sided, 2-sided-long-edge
        - default is 2-sided-long-edge
     - Job scheduling attributes for this Printer are:
          - job-priority = 1,2,3
        - default = 3

11.17.2. Printer Capabilities


An end-user wants to determine the resolution, marking technology, and
PDLs supported by the printer.

Client                                        IPP Printer
   +---------------------------------------------------------- >
     Please tell me the
     - resolution of the printer
     - the marking technology of the printer
     - PDLs supported
   < ----------------------------------------------------------+
     Printer resolution  = 600 dpi
     Marking Technology = laser
     PDLs supported = Postscript level 2, PCL/6










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11.18. GETTING STATUS
11.18.1. Printer State/Status


An end-user wants to determine the state or status of the printer.

Client                                        IPP Printer

   +---------------------------------------------------------- >
     What is the state of the printer?

   < ----------------------------------------------------------+
     Printer state = out-of-paper

11.18.2. Job Status


An end user wants to get the status of a job he has submitted.

Client                                        IPP Printer

   +---------------------------------------------------------- >
     Please tell me the status of job #12345

   < ----------------------------------------------------------+
     Job #12345 is queued
     it is number 3 in the queue
     printer state = printing


11.18.3. Status of All My Jobs


An end user wants to get a list of all of the jobs he has submitted to
this Printer.

Client                                        IPP Printer

   +---------------------------------------------------------- >
     Please tell me the status of my jobs

   < ----------------------------------------------------------+
     Job #00012 is complete
     Printed at 12:35 on 01/23/97

     Job #09876 is printing

     Job #12345 is queued
     it is number 3 in the queue

     Job #34567 is queued
     it is number 7 in the queue


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11.19. ASYNCHRONOUS NOTIFICATION
11.19.1. Job Completion


An end-user wants to get notification of events that affect his print
jobs. Print job completes without error.

Client                                        IPP Printer

   < ----------------------------------------------------------+
     Print job #123 completed

11.19.2. Job Complete with Data


An end-user wants to get notification of events that affect his print
jobs. Print job completes, users asked for all end of job information.

Client                                        IPP Printer

   < ----------------------------------------------------------+
     Print job #123 completed
     - total pages printed = 15
     - number of copies printed = 3
     - total cost to print = $7.45
     - pick up copies in room H-6, building 005

11.19.3. Print Job Fails


An end-user wants to get notification of events that affect his print
jobs. Print job fails. Printer is unattended.

Client                                        IPP Printer

   < ----------------------------------------------------------+
     Print job #123 failed
     - total pages printed = 15
     - number of pages submitted = 25
     - printer-state = jammed















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11.20. CANCEL A JOB


The end-user submits a print job and later decides to cancel it.

Client                                        IPP Printer

   +---------------------------------------------------------- >
   < ----------------------------------------------------------+
     Authentication.


   +---------------------------------------------------------- >
     Cancel job #1234

   < ----------------------------------------------------------+
     Job #1234 Canceled




































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                      Expires: May 16, 1999




INTERNET DRAFT   Internet Printing Design Goals    Nov. 16, 1998



11.21. END TO END SCENARIO - WITHIN AN ENTERPRISE


An office worker prints on shared departmental printers. All printers in
the office are public, that is, no authentication or authorization is
required. Printers are protected from external access by a firewall. No
billing or accounting is required. Most printing is done from desktop
applications. A help desk is provided for printing problems. Standard
operating systems and applications are used. Drivers are available, but
are installed manually by support personnel. This scenario assumes that
drivers have been installed and that drivers are not IPP aware, that is,
they cannot communicate across an IPP connection to obtain status and
capabilities. IPP printers appear in application pull-down menus.
Printer configuration data is hard wired into the driver.

End-user selects print from the application pull down menu. An IPP
printer is selected from the list of Printers offered

The driver puts up a dialogue with hard-wired set of options
for this printer. The end-user makes choices and submits job.


Client                                        IPP Printer
   +---------------------------------------------------------- >
     Here is a print job
     - job-name = memo-to-boss
     - notify me by email when job is complete
     - print on us-letter-white paper
     - print 1 copy
     - print at normal quality
     - print on 1 side
     - give me the state of the printer in response

The driver generates the print data and passes it to the IPP driver a
piece at a time as it is generated.

   +---------------------------------------------------------- >
     Here is the print data


   < ----------------------------------------------------------+
     Print data received, file is spooled
     - printer state = printing
     - time submitted = 2/12/97, 15:35
     - current job state = spooled


Client adds this job to list of current jobs. List of jobs and state of
each is available on a pull-down menu on the client.

End-user selects job #1234 from list and clicks on it to see its status.


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   +---------------------------------------------------------- >
     Give me the state of job #1234
     and the state of the Printer

   < ----------------------------------------------------------+
     Job #1234 state = spooled
     - it is number 3 in the queue
     - printer state = printing

The job completes without error

   < ----------------------------------------------------------+
     Job #1234 completed
     12 of 12 pages printed






































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11.22. END TO END SCENARIO - ACROSS ENTERPRISES


An office worker in Company A needs to print an office document on a
"public" printer at Company B, a business partner. Both companies have
corporate firewalls so the print request must flow out of A's firewall
and into B's firewall. The office worker can look at public printers in
Company B's directory service. The document is generated by a desktop
application. Since the printer is "public" no authentication or
authorization is required.  A driver is downloaded. The driver is IPP
aware, that is, it can communicate dynamically through the IPP protocol
layer to obtain information about the printer.

Client                      Company B's Directory Service

End user connects to B's Directory service

   +---------------------------------------------------------- >
     Find a Printer with these characteristics
     - public (no authorization or authentication required)
     - is in Lexington, building 004
     - prints black and white

   < ----------------------------------------------------------+
     Printer "Public-A"
     - http://www.lexmark.com/pubprinter/a

     Printer "Public-B"
     - http://www.lexmark.com/pubprinter/b

End user selects Public-A

Client                                           Public-A

   +---------------------------------------------------------- >
     Where can I find a driver for you?

   < ----------------------------------------------------------+
     Drivers at http://www.lexmark.com/pubprinters/a/os245

End user gets driver and installs it on his PC.

End-user selects print from the application pull down menu. "Public-A"
is selected from the list of Printers offered

   +---------------------------------------------------------- >
     I'm going to submit a print job
     give me your job submission attributes

   < ----------------------------------------------------------+


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INTERNET DRAFT   Internet Printing Design Goals    Nov. 16, 1998


     Production attributes for this Printer are:
     - medium-select = us-letter-white, us-legal-white
        - default is us-letter-white
        -   copies = 1,2,3,4,5
        - default is 1
             - print-quality = draft, normal, high
        - default is draft
             - sides = 1-sided, 2-sided-long-edge
        - default is 2-sided-long-edge

     Job scheduling attributes for this Printer are:
     - job-priority = 1,2,3
        default = 3

Driver puts up dialogue with available options and fills in the
defaults.

End-user makes choices and submits job

   +---------------------------------------------------------- >
     Here is a print job
     - job-name = memo-to-Don-Wright
     - notify me by email when job is complete
     - print on us-letter-white paper
     - print 1 copy
     - print at normal quality
     - print on 1 side
     - give me the state of the printer in response


The driver generates the print data and passes it to the IPP driver a
piece at a time.

   +---------------------------------------------------------- >
     Here is the print data

   < ----------------------------------------------------------+
     Print data received, and spooling started
     print job id = #1234

     Print data received, file is spooled

     - printer state = printing
     - time submitted = 2/12/97, 15:35
     - current job state = spooled


Client adds this job to list of current jobs.  List of jobs and state of
each is available on a pull-down menu on the client.

End-user selects job #1234 from list and clicks on it to see its status.


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   +---------------------------------------------------------- >
     Give me the state of job #1234
     and the state of the Printer

   < ----------------------------------------------------------+
     Job #1234 state = spooled
     - it is number 3 in the queue
     - printer state = printing

    * The job completes without error
   < ----------------------------------------------------------+
     Job #1234 completed
     12 of 12 pages printed







































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INTERNET DRAFT   Internet Printing Design Goals    Nov. 16, 1998



11.23. END TO END SCENARIO - ON THE INTERNET


An executive in her hotel room is finishing an important presentation on
her laptop computer. She connects to a local print shop through the web
to get a copy of her charts printed for tomorrow's presentation. She
must find a print shop that is convenient and can print color
transparencies. She must download and temporarily install a driver in
order to generate the PDL required by the print shop. Mutual
authentication is required by the print shop and payment must be made in
advance. The job is encrypted on the wire to prevent eavesdropping.

End-user completes presentation. She goes to the web and connects
to the SirZippy home page.

   Client                      SirZippy Directory Service
   +---------------------------------------------------------- >

     Find me a printer with these characteristics
     - Near Market Street in San Jose
     - Prints color transparencies
     - drivers can be downloaded
     - supports privacy (encryption)
     -

Available Printers matching these characteristics are looked up in the
Directory Service

   < ----------------------------------------------------------+

     Printer "Color-A"
     - located at 123 First Street in San Jose
     - URI is http://www.SirZippy.com/FirstStreet/Color-A
     - prints color transparencies
     - 600 dpi laser
     - driver ABC-Postscript-V1.3 available at this URI
     - cost = $.75 per page
     - authentication required to use printer
     - payment required prior to printing


     Printer "Color-B"
     - located at 67 San Carlos Street, San Jose
     - URI is http://www.SirZippy.com/SanCarlos/Color-B
     - prints color transparencies
     - 1200 dpi laser
     - driver XYZ-PostScript-V4.3 available at this URI
     - cost = $1.25 per page
     - authentication required to use printer
     - payment required prior to printing
     -


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INTERNET DRAFT   Internet Printing Design Goals    Nov. 16, 1998


     - more information at this URI

The user decides to use the first printer because it is closer. She
connects to the URI given to get a driver.

Client                                         Driver URI

   +---------------------------------------------------------- >
     I need a driver for "Color-A"


   < ----------------------------------------------------------+
      Driver installer is at http://www.xerox.com/prtdrvrs

     Driver is installed

     User connects to
     "Color-A"

Client                              IPP Printer "Color-A"

   +---------------------------------------------------------- >
   < ----------------------------------------------------------+
     Mutual authentication and exchange of secret keys

   +---------------------------------------------------------- >
     I'm going to submit a print job
     give me your job submission attributes

   < ----------------------------------------------------------+
     Production attributes for this Printer are:
     - medium-select = us-letter-white, us-legal-white
          - default is us-letter-white
     - copies = 1,2,3,4,5
          - default is 1
     - print-quality = draft, normal, high
          - default is draft
     - sides = 1-sided, 2-sided-long-edge
          - default is 2-sided-long-edge

     Job scheduling attributes for this Printer are:
     - job-priority = 1,2,3
        default = 3

Driver puts up dialogue with available options and fills in the
defaults.

End-user makes choices and submits job

   +---------------------------------------------------------- >
      Here is a print job


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INTERNET DRAFT   Internet Printing Design Goals    Nov. 16, 1998


     - job-name = presentation
     - notify me by email when job is complete
     - print on us-letter-transparency
     - print 1 copy
     - print at high quality
     - print by 9:00 am tomorrow morning
     - give me the state of the printer in response

The driver generates the print data and passes it to the IPP  driver a
piece at a time.

   +---------------------------------------------------------- >
    Here is the print data

    < ---------------------------------------------------------+
    Print data received, and spooling started
    print job id = #1234

    Print data received, file is spooled
     - printer state = printing
     - time submitted = 2/12/97, 15:35
     - current job state = held, waiting for payment

   +---------------------------------------------------------- >
   < ----------------------------------------------------------+
     Payment transaction

   < ----------------------------------------------------------+
     Job is scheduled to print, pick up after 9:00am tomorrow
     Thank you for using SirZippy























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