Network Working Group                                       F.D. Wright
Request for Comments: 2567                        Lexmark International
Category: Experimental                                       April 1999


            Design Goals for an Internet Printing Protocol

Status of this Memo

  This memo defines an Experimental Protocol for the Internet
  community.  It does not specify an Internet standard of any kind.
  Discussion and suggestions for improvement are requested.
  Distribution of this memo is unlimited.

Copyright Notice

  Copyright (C) The Internet Society (1999).  All Rights Reserved.

IESG Note

  This document defines an Experimental protocol for the Internet
  community.  The IESG expects that a revised version of this protocol
  will be published as Proposed Standard protocol.  The Proposed
  Standard, when published, is expected to change from the protocol
  defined in this memo.  In particular, it is expected that the
  standards-track version of the protocol will incorporate strong
  authentication and privacy features, and that an "ipp:" URL type will
  be defined which supports those security measures.  Other changes to
  the protocol are also possible.  Implementers are warned that future
  versions of this protocol may not interoperate with the version of
  IPP defined in this document, or if they do interoperate, that some
  protocol features may not be available.

  The IESG encourages experimentation with this protocol, especially in
  combination with Transport Layer Security (TLS) [RFC2246], to help
  determine how TLS may effectively be used as a security layer for
  IPP.

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



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  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.

  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 [RFC2568]
  Internet Printing Protocol/1.0: Model and Semantics [RFC2568]
  Internet Printing Protocol/1.0: Encoding and Transport [RFC2565]
  Internet Printing Protocol/1.0: Implementer's Guide [ipp-iig]
  Mapping between LPD and IPP Protocols [RFC2569]

  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.....................................................4
  2. TERMINOLOGY......................................................4
  3. DESIGN GOALS.....................................................6
  3.1. End-user.......................................................6
  3.1.1. Finding or locating a printer................................6
  3.1.2. Create an instance of the printer............................7
  3.1.3. Viewing the status and capabilities of a printer.............7
  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........................................9
  3.2. Operator (NOT REQUIRED FOR V1.0)...............................9
  3.2.1. Alerting.....................................................9
  3.2.2. Changing Print and Job Status...............................10
  3.3. Administrator (NOT REQUIRED FOR v1.0).........................10
  4. OBJECTIVES OF THE PROTOCOL......................................10
  4.1. SECURITY CONSIDERATIONS.......................................11
  4.2. Interaction with LPD (RFC1179)................................12
  4.3. Extensibility.................................................12
  4.4. Firewalls.....................................................13
  4.5. Internationalization..........................................13
  5. IPP SCENARIOS...................................................13
  5.1. Printer Discovery.............................................14
  5.2. Driver Installation...........................................15
  5.3. Submitting a Print Job........................................15
  5.4. Getting Status/Capabilities...................................16
  5.5. Asynchronous Notification.....................................17
  5.6. Job Canceling.................................................17
  6. Security Considerations.........................................18
  7. REFERENCES......................................................18
  8. ACKNOWLEDGMENTS.................................................19
  9. AUTHOR'S ADDRESS................................................19
  10. APPENDIX - DETAILED SCENARIOS..................................20
  10.1. Printer discovery within an enterprise.......................20
  10.2. Printer discovery across enterprises.........................21
  10.3. Printer discovery on the Internet -logical operations........21
  10.4. Printer discovery on the Internet - authentication...........22
  10.5. Driver Download..............................................23
  10.6. Submitting a print job as a file.............................24
  10.7. Submitting a print job with two documents....................24
  10.8. Submitting a print job as a file, printing fails.............25
  10.9. Submitting a print job with authentication, PRIVACY and
        payment......................................................26
  10.10. Submitting a print job with decryption error................27
  10.11. Submitting a print job with authentication..................28
  10.12. Submitting a print job generated dynamically................29
  10.13. Submitting a print job with a Printer jam - CANCELED........29



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  10.14. Submitting a print job with a Printer jam - recovered.......30
  10.15. Submitting a print job with server pull.....................31
  10.16. Submitting a print job with referenced resources............32
  10.17. Getting Capabilities........................................33
  10.17.1. Submission Attributes.....................................33
  10.17.2. Printer Capabilities......................................33
  10.18. Getting Status..............................................34
  10.18.1. Printer State/Status......................................34
  10.18.2. Job Status................................................34
  10.18.3. Status of All My Jobs.....................................34
  10.19. Asynchronous Notification...................................35
  10.19.1. Job Completion............................................35
  10.19.2. Job Complete with Data....................................35
  10.19.3. Print Job Fails...........................................35
  10.20. Cancel a job................................................36
  10.21. End to end Scenario - within an enterprise..................36
  10.22. End to end Scenario - across enterprises....................37
  10.23. End to End Scenario - on the internet.......................40
  11. Full Copyright Statement.......................................43

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



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  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:

  - 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



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  the protocol (e.g. V2.0) may include support for these initially
  excluded wants and needs.

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






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  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.

  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)




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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 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:



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  - 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.

  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 printed 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



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  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.

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.

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).



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  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 10 (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.





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

        * 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.

5. IPP SCENARIOS

  Each of the scenarios in this section describes a specific IPP
  operation, such as submitting a print job. Section 10 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







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  Responses could additionally include:

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

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



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  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.

  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











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  - Job submission attributes supported/required
     - scheduling attributes (e.g. priority)
     - production attributes (e.g. number of copies)

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.

7. REFERENCES

  [ipp-iig]  Hastings, T. and C. Manros, "Internet Printing
             Protocol/1.0: Implementer's Guide", Work in Progress.

  [RFC2569]  Herriot, R., Hastings, T., Jacobs, N. and J. Martin,
             "Mapping between LPD and IPP Protocols", RFC 2569, April
             1999.

  [RFC2566]  deBry, R., Hastings, T., Herriot, R., Isaacson, S. and P.
             Powell, "Internet Printing Protocol/1.0: Model and
             Semantics", RFC 2568, April 1999.

  [RFC2565]  Herriot, R., Butler, S., Moore, P. and R. Tuner, "Internet
             Printing Protocol/1.0: Encoding and Transport", RFC 2565,
             April 1999.

  [RFC2568]  Zilles, S., "Rationale for the Structure and Model and
             Protocol for the Internet Printing Protocol", RFC 2568,
             April 1999.

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

  [RFC1179]  McLaughlin, L., "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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8. 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                           Utah Valley State College
  [email protected]             [email protected]

  Carl-Uno Manros                  Robert Herriot
  Xerox                            Sun
  [email protected]         [email protected]

  Tom Hastings                     Peter Zehler
  Xerox                            Xerox
  [email protected]       [email protected]

9. 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
  EMail: [email protected]






















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10. 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.

10.1. 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

10.2. 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

10.3. 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.



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  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

10.4. 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







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       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

10.5. 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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10.6. 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

10.7. 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

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



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       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

10.8. 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





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10.9. 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

     +---------------------------------------------------------- >
       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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10.10. 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



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RFC 2567             Internet Printing Design Goals           April 1999


       - no pages printed
       - current state of job = aborted

10.11. 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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RFC 2567             Internet Printing Design Goals           April 1999


10.12. 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

10.13. 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



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       - 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

10.14. 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

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



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RFC 2567             Internet Printing Design Goals           April 1999


       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

10.15. 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

       .
       .
      < ----------------------------------------------------------+



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RFC 2567             Internet Printing Design Goals           April 1999


       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

10.16. 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



Wright                        Experimental                     [Page 32]

RFC 2567             Internet Printing Design Goals           April 1999


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

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

10.17. GETTING CAPABILITIES

10.17.1. 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

10.17.2. 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



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RFC 2567             Internet Printing Design Goals           April 1999


       PDLs supported = Postscript level 2, PCL/6

10.18. GETTING STATUS

10.18.1. 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

10.18.2. 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

10.18.3. 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



Wright                        Experimental                     [Page 34]

RFC 2567             Internet Printing Design Goals           April 1999


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

10.19. ASYNCHRONOUS NOTIFICATION

10.19.1. 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

10.19.2. 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

10.19.3. 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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RFC 2567             Internet Printing Design Goals           April 1999


10.20. 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


10.21. 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



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RFC 2567             Internet Printing Design Goals           April 1999


       - 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.

     +---------------------------------------------------------- >
       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

10.22. 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.



Wright                        Experimental                     [Page 37]

RFC 2567             Internet Printing Design Goals           April 1999


  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

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

       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




Wright                        Experimental                     [Page 38]

RFC 2567             Internet Printing Design Goals           April 1999


       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.

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

     < ----------------------------------------------------------+
       Job #1234 state = spooled



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RFC 2567             Internet Printing Design Goals           April 1999


       - it is number 3 in the queue
       - printer state = printing

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

10.23. 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




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RFC 2567             Internet Printing Design Goals           April 1999


       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
       - 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



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RFC 2567             Internet Printing Design Goals           April 1999


       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 = 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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RFC 2567             Internet Printing Design Goals           April 1999


11.  Full Copyright Statement

  Copyright (C) The Internet Society (1999).  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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