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rfc:rfc2567

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

Wright Experimental [Page 1] RFC 2567 Internet Printing Design Goals April 1999

 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.

Wright Experimental [Page 2] RFC 2567 Internet Printing Design Goals April 1999

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

Wright Experimental [Page 3] RFC 2567 Internet Printing Design Goals April 1999

 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

Wright Experimental [Page 4] RFC 2567 Internet Printing Design Goals April 1999

 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:
  1. An IPP client talking to an IPP Printer object imbedded in a

single, physical output device.

  1. 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

Wright Experimental [Page 5] RFC 2567 Internet Printing Design Goals April 1999

 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:
  1. by name (Printer 1, Joes-color-printer, etc.)
  2. by geographic location (bldg 1, Kentucky, etc.)
  3. 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:
  1. inside a functional sub-domain
  2. include only a particular domain (lexmark.com)
  3. exclude specified domains

Wright Experimental [Page 6] RFC 2567 Internet Printing Design Goals April 1999

 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.:
  1. supported media, commonly paper, by size and type
  2. paper handling capability, e.g. duplex, collating, finishing
  3. color capability
 When checking the status of the printer and its print jobs, the end-
 user typically wants to be able to determine:
  1. is the printer on-line?
  2. what are the defaults to be used for printing?
  3. how many jobs are queued for the printer?
  4. how are job priorities assigned? (outside the scope of IPP)

Wright Experimental [Page 7] RFC 2567 Internet Printing Design Goals April 1999

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):
  1. the end-user selects the correct printer driver
  2. the printer automatically selects the proper interpreter
  3. 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:
  1. rejecting the print job
  2. redirecting the print job to another printer (Not in V1.0)
  3. 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:

Wright Experimental [Page 8] RFC 2567 Internet Printing Design Goals April 1999

  1. number of copies
  2. single or two sided printing
  3. finishing
  4. 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

Wright Experimental [Page 9] RFC 2567 Internet Printing Design Goals April 1999

 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:
  1. create an instance of a printer
  2. create, edit and maintain the list of authorized end-users
  3. create, edit and maintain the list of authorized operators
  4. create, edit and maintain the list of authorized

administrators

  1. 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).

Wright Experimental [Page 10] RFC 2567 Internet Printing Design Goals April 1999

 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.

Wright Experimental [Page 11] RFC 2567 Internet Printing Design Goals April 1999

 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:
  1. defective software
  2. malicious software (e.g. Trojan horses)
  3. 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:
  1. by providing a process whereby implementers can submit proposals

for registration of new attributes and new enumerated values for

    existing attributes.

Wright Experimental [Page 12] RFC 2567 Internet Printing Design Goals April 1999

  • 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.

  1. by providing syntax in the protocol so that implementers may add

private (i.e. unregistered) attributes and enumerated attribute

    values.
  1. 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.

Wright Experimental [Page 13] RFC 2567 Internet Printing Design Goals April 1999

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:
  1. capabilities of the Printer, e.g. PDLs supported
  2. physical location, e.g. in building 010
  3. driver required and location
  4. cost per page to print (outside the scope of IPP)
  5. whether or not printer is access controlled
  6. whether or not usage requires client authentication
  7. whether or not Printer can be authenticated
  8. whether or not payment is required for printing (outside the scope

of IPP)

  1. maximum job size (spool size) (outside the scope of IPP)
  2. whether or not Printer support compression (outside the scope of

IPP)

  1. whether or not Printer supports encryption
  2. administrative limits on this Printer
    1. maximum number of copies per job
    2. maximum number of pages per job

Wright Experimental [Page 14] RFC 2567 Internet Printing Design Goals April 1999

 Responses could additionally include:
  1. how to get more information
    1. web page
    2. telephone number
    3. 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:
  1. Print data is a file submitted with the job
  2. Print data is generated on the fly by an application
  3. Print data is a file referenced by a URI

Wright Experimental [Page 15] RFC 2567 Internet Printing Design Goals April 1999

 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:
  1. Got the print job and queued it
  2. Got the print job and am printing it
  3. Got the print job, started to print it, but printing failed
    1. why it failed (e.g. unrecoverable PostScript error)
    2. state of the printer
    3. how much printed
  4. Got the print job but couldn't print it
    1. why it can't be printed
    2. state of the printer
  5. Got the print job but don't know what to do with it
  6. 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
  1. Static capabilities of the device
  2. Dynamic state of the Printer (e.g. out of paper)
  3. State of a specific job owned by this client
  4. State of all jobs owned by this client
    1. queued
    2. printing
    3. completed

Wright Experimental [Page 16] RFC 2567 Internet Printing Design Goals April 1999

  1. Job submission attributes supported/required
    1. scheduling attributes (e.g. priority)
    2. 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
  1. job completion
  2. a fatal error that requires the job to be resubmitted
  3. 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.

Wright Experimental [Page 17] RFC 2567 Internet Printing Design Goals April 1999

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.

Wright Experimental [Page 18] RFC 2567 Internet Printing Design Goals April 1999

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
 sisaacson@novell.com             debryro@uvsc.edu
 Carl-Uno Manros                  Robert Herriot
 Xerox                            Sun
 manros@cp10.es.xerox.com         Robert.Herrior@pahv.xerox.xom
 Tom Hastings                     Peter Zehler
 Xerox                            Xerox
 hastings@cp10.es.xerox.com       Peter.Zehler@usa.xerox.com

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: don@lexmark.com

Wright Experimental [Page 19] RFC 2567 Internet Printing Design Goals April 1999

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

Wright Experimental [Page 20] RFC 2567 Internet Printing Design Goals April 1999

  1. driver XYZ-Postscript-V2.4 required, here is URI
  2. cost is $1.25 page for color transparencies
  3. limit is 5 pages per job
  4. authentication is required to use printer
  5. printer is unattended
  6. 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.

Wright Experimental [Page 21] RFC 2567 Internet Printing Design Goals April 1999

 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

Wright Experimental [Page 22] RFC 2567 Internet Printing Design Goals April 1999

      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

Wright Experimental [Page 23] RFC 2567 Internet Printing Design Goals April 1999

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

Wright Experimental [Page 24] RFC 2567 Internet Printing Design Goals April 1999

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

Wright Experimental [Page 25] RFC 2567 Internet Printing Design Goals April 1999

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

Wright Experimental [Page 26] RFC 2567 Internet Printing Design Goals April 1999

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

Wright Experimental [Page 27] RFC 2567 Internet Printing Design Goals April 1999

  1. no pages printed
  2. 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

Wright Experimental [Page 28] 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

Wright Experimental [Page 29] RFC 2567 Internet Printing Design Goals April 1999

  1. return status of the printer in response
  2. document is in Postscript format
  3. 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
    < ----------------------------------------------------------+

Wright Experimental [Page 30] 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
  1. job name = MyJob
  2. notify me by email when done printing
  3. print on iso-a4-white paper
  4. print on both sides of the paper
  5. return status of the printer in response
  6. 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
      .
      .
     < ----------------------------------------------------------+

Wright Experimental [Page 31] 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

Wright Experimental [Page 33] 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

Wright Experimental [Page 35] 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

Wright Experimental [Page 36] RFC 2567 Internet Printing Design Goals April 1999

  1. 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
  1. printer state = printing
  2. time submitted = 2/12/97, 15:35
  3. 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

Wright Experimental [Page 39] RFC 2567 Internet Printing Design Goals April 1999

  1. it is number 3 in the queue
  2. 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

Wright Experimental [Page 40] 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

Wright Experimental [Page 41] 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
  1. job-name = presentation
  2. notify me by email when job is complete
  3. print on us-letter-transparency
  4. print 1 copy
  5. print at high quality
  6. print by 9:00 am tomorrow morning
  7. 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

Wright Experimental [Page 42] 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.

Wright Experimental [Page 43]

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