[Search] [txt|pdf|bibtex] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02 03 04                                                
INTERNET-DRAFT
<draft-ietf-ipp-install-01.txt>
                                                              Hugo Parra
                                                            Novell, Inc.
                                                             Ted Tronson
                                                            Novell, Inc.
                                                            Tom Hastings
                                                             Xerox Corp.
                                                        November 7, 2000

                   Internet Printing Protocol (IPP):

                     Printer Installation Extension


    Copyright (C) The Internet Society (2000). All Rights Reserved.


Status of this Memo

This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of [RFC2026].  Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas, and
its working groups.  Note that other groups may also distribute working
documents as Internet-Drafts.

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

The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt

The list of Internet-Draft Shadow Directories can be accessed as
http://www.ietf.org/shadow.html.


Abstract

Various client platforms require that some setting up take place at the
workstation before the client can properly submit jobs to a specific
printer.   This setup process is sometimes referred to as printer
installation.  Most clients need some information about the printer
being installed as well as support files to complete the printer
installation.  The nature of the support files varies depending on the
specific client platform, from simple configuration files to highly
sophisticated printer drivers.  This document refers to these support
files as "Client Print Support Files".  Traditionally, the selection and
installation of the correct Client Print Support Files has been error
prone.  The selection and installation process can be simplified and
even automated if the workstation can learn some key information about
the printer and which sets of Client Print Support Files are available.
Such key information includes: operating system type, CPU type,
document-format (PDL), natural language, etc. This document describes
the IPP extensions that enable workstations to obtain the information
needed to perform a proper printer driver installation using IPP.


Parra, Tronson, Hastings                                       [page 1]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


The full set of IPP documents includes:

  Design Goals for an Internet Printing Protocol [RFC2567]
  Rationale for the Structure and Model and Protocol for the Internet
     Printing Protocol [RFC2568]
  Internet Printing Protocol/1.1: Model and Semantics [RFC2911]
  Internet Printing Protocol/1.1: Encoding and Transport [RFC2910]
  Internet Printing Protocol/1.1: Implementer's Guide [ipp-iig]
  Mapping between LPD and IPP Protocols [RFC2569]

The "Design Goals for an Internet Printing Protocol" document takes a
broad look at distributed printing functionality, and it enumerates
real-life scenarios that help to clarify the features that need to be
included in a printing protocol for the Internet.  It identifies
requirements for three types of users: end users, operators, and
administrators.  It calls out a subset of end user requirements that are
satisfied in IPP/1.0.  A few OPTIONAL operator operations have been
added to IPP/1.1.

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
specification documents, and gives background and rationale for the IETF
working group's major decisions.

The "Internet Printing Protocol/1.1: Encoding and Transport" document is
a formal mapping of the abstract operations and attributes defined in
the model document onto HTTP/1.1 [RFC2616].  It defines the encoding
rules for a new Internet MIME media type called "application/ipp".  This
document also defines the rules for transporting a message body over
HTTP whose Content-Type is "application/ipp".  This document defines a
new scheme named 'ipp' for identifying IPP printers and jobs.

The "Internet Printing Protocol/1.1: Implementer's Guide" document gives
insight and advice to implementers of IPP clients and IPP objects.  It
is intended to help them understand IPP/1.1 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.












Parra, Tronson, Hastings                                       [page 2]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000





                           Table of Contents

1  Introduction......................................................4
2  Terminology.......................................................4
3  Model Extensions..................................................4
 3.1  client-print-support-files-supported (1setOf octetString(MAX)).5
 3.2  Get-Printer-Attributes Operation Extension.....................9
   3.2.1 Get-Printer-Attributes Request..............................9
     3.2.1.1 client-print-support-files-filter (octetString(MAX))
     operation attribute..............................................9
   3.2.2 Get-Printer-Attributes Response............................11
 3.3  Get-Client-Print-Support-Files................................12
   3.3.1 Get-Client-Print-Support-Files Request.....................12
   3.3.2 Get-Client-Print-Support-Files Response....................13
4  Conformance......................................................14
5  Encoding of the Operation Layer..................................14
6  Encoding of Transport Layer......................................14
7  IANA Considerations..............................................15
8  Internationalization Considerations..............................15
9  Security Considerations..........................................15
10   References......................................................15
11   Author's Addresses..............................................16
12   Full Copyright Statement........................................17



                                 Tables

Table 1 - "client-print-support-files-supported" attribute fields.....7

Table 2 - "client-print-support-files-filter" attribute fields.......10






















Parra, Tronson, Hastings                                       [page 3]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


1  Introduction

A common configuration for printing from a workstation requires that
some Client Print Support Files (e.g., PPD, printer driver files)
specific to the target printer be installed on that workstation.
Selection and configuration of the appropriate Client Print Support
Files can be simplified and even automated if the workstation can obtain
some key information about the printer and which sets of Client Print
Support Files are available.  Such key information includes: operating
system type, CPU type, document-format (PDL), natural language, etc.
With a few extensions, IPP provides a simple and reliable vehicle for
printers to convey this information to interested workstations.  The IPP
extensions described in this document enable a flexible solution for
installing Client Print Support Files on workstations running different
operating systems and for printers of all makes and models.  It allows
Client Print Support Files to be downloaded from repositories of
different sorts.  A possible repository for the files is the printer
itself.  The extensions necessary for getting Client Print Support Files
from the printer are included in this document.


2  Terminology

Client Print Support Files - a set of files, such as a printer driver,
font metric file, printer configuration file (PPD, GPD, etc.) that
support a client printing to a particular Printer.  A Printer can have
multiple sets of Client Print Support Files that work for different
operating systems, document formats, natural languages, CPUs, etc.

This document uses terms such as "attributes", "keywords", and
"support".  These terms have special meaning and are defined in the
model terminology [RFC2911] section 12.2.

Capitalized terms, such as MUST, MUST NOT, REQUIRED, SHOULD, SHOULD NOT,
MAY, NEED NOT, and OPTIONAL, have special meaning relating to
conformance.  These terms are defined in [RFC2911] section 12.1 on
conformance terminology, most of which is taken from RFC 2119 [RFC2119].

This section defines the following additional terms that are used
throughout this document:

  REQUIRED: if an implementation supports the extensions described in
     this document, it MUST support a REQUIRED feature.
  OPTIONAL: if an implementation supports the extensions described in
     this document, it MAY support an OPTIONAL feature.

3  Model Extensions

To assist workstations in the printer installation process, an IPP
printer needs to provide the workstation with information about the
Client Print Support Files, such as the their name and location/s.  This
information needs to match the workstation's specific environment, such
as its operating system, preferred natural language, and preferred
document format.


Parra, Tronson, Hastings                                       [page 4]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


The following extensions to the IPP model enable assisted or automated
printer installation.  This section describes each extension in detail.

     - A new REQUIRED Printer Description attribute: "client-print-
       support-files-supported" (1setOf octetString(MAX)).

     - A new REQUIRED Get-Printer-Attributes operation attribute:
       "client-print-support-files-filter" (octetString(MAX)).

     - A new RECOMMENDED printer operation: Get-Client-Print-Support-
       Files.


3.1 client-print-support-files-supported (1setOf octetString(MAX))


An IPP Printer uses the REQUIRED Printer Description attribute "client-
print-support-files-supported" to represent relevant information about
all of the Client Print Support Files it supports.  Each value is a
composite UTF-8 string with well-defined fields (see Table 1).  Each
value string MUST be formatted as follows:

 "uri=val < field-name =val  ,.,val  < . < field-name =val  ,.,val  <"
         1            2    21      2p                n    n1      nq


The first field MUST be the "uri" field.  The remaining fields MAY be in
any order.


The string MUST NOT include any control characters (hex 00 to 1F), even
the so-called white space control characters (TAB, CR, and LF) anywhere.
Only zero or more UTF-8 SPACE characters (hex 20) can be included and
they can be included only IMMEDIATELY AFTER the punctuation character:
"<", but NOT anywhere else, including after "=" and ",".  However, if
the UTF-8 SPACE character is needed in a file name value, then each
occurrence is included directly, without escaping (see example).  On the
other hand, if the UTF-8 SPACE character is needed in a URL value, then
each occurrence is escaped as: "\x20" (URI conventions - see [RFC2396]).


Table 1 lists the REQUIRED fields that a Printer MUST support and the
OPTIONAL fields that a Printer MAY support in the "client-print-support-
files-supported" (1setOf octetString(MAX)) Printer Description
attribute.  A Printer implementation MAY support additional fields using
the same syntax.  Values are defined to be either CASE-SENSITIVE or ALL-
LOWER-CASE according to the definitions for the attribute syntaxes from
[RFC2911] (set off by single quotes in the table).  The CASE-SENSITIVE
values MAY have upper and lower case letters as for the corresponding
attribute syntaxes in [RFC2911].  The LOWER-CASE values MUST have all
lower case alphabetic letters.  Additional characters, such as digits,
hyphen-minus (-), period (.), and slash (/) are according to the
corresponding attribute syntaxes in [RFC2911].





Parra, Tronson, Hastings                                       [page 5]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


Clients SHOULD ignore fields they don't recognize in a given value.
This allows for future extensions to the format of the string without
breaking compatibility with earlier clients.



















































Parra, Tronson, Hastings                                       [page 6]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


   Table 1 - "client-print-support-files-supported" attribute fields

Field name     Field value


"uri"          One REQUIRED CASE-SENSITIVE 'uri' string identifying the
               uri where to obtain the support files for each OS
               platform, document format, and natural language the
               printer supports.  This MUST be the first field in each
               value.  Examples of uri schemes that MAY be found here
               are ftp, http, and ipp.  The ftp and http schemed URIs
               identify the archive file that contains all the
               necessary client support files.  The ipp schemed URIs
               also identify the archive file which may be obtained
               from the Printer using the Get-Client-Print-Support-
               Files operation (see section 3.3).  In order to
               distinguish between multiple Client Print Support Files,
               the ipp URL is used to distinguish between them in an
               implementation dependent manner, such as using a file
               URL parameter (' file=xxx).  A Printer SHOULD support
               the ipp scheme.

"os-type"      One or more REQUIRED comma-separated LOWER-CASE strings
               identifying the operating system types supported by this
               set of Client Print Support Files.  Valid values include
               the operating system names defined in the IANA document
               [os-names]. Although the IANA registry requires that the
               names be all upper-case, the values MUST be all lower
               case in this field (plus hyphen-minus (-), period (.),
               and slash (/)).   Examples: linux, linux-2.2, os/2, sun-
               os-4.0, unix, unix-bsd, win32, windows-95, windows-98,
               windows-ce, windows-nt, windows-nt-4, windows-nt-5.

"cpu-type"     One or more REQUIRED comma-separated LOWER-CASE strings
               identifying the CPU types supported by this set of
               Client Print Support Files. Values (or compatible):
               'unknown', 'x86-16', 'x86-32', 'x86-64', 'dec-vax',
               'alpha', 'power-pc', 'm-6800', 'sparc', 'itantium',
               'mips', 'arm'.

"document-     One or more REQUIRED comma-separated CASE-SENSITIVE
format"        'document-format' strings identifying the document
               formats supported by this set of Client Print Support
               Files.  Valid values are the string representation of
               the IPP mimeMediaType syntax (see [RFC2911]).  'unknown'
               is a valid value.

"natural-      One or more REQUIRED comma-separated LOWER-CASE
language"      'naturalLanguage' strings identifying the natural
               language used by this set of Client Print Support Files.
               Valid values are the string representation of the IPP
               naturalLanguage syntax.  'unknown' is a valid value.

"compression"  One REQUIRED LOWER-CASE 'keyword' string identifying the
               mechanism used to compress this set of Client Print
               Support Files.  All files needed for the installation of


Parra, Tronson, Hastings                                       [page 7]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


Field name     Field value


               a printer driver MUST be compressed into a single file.
               Valid values are: 'deflate', 'gzip', 'compress'.  The
               'none' value is allowed but limits the uncompressed
               Client Print Support File to a single file.

"file-type"    One or more REQUIRED comma-separated LOWER-CASE
               'keyword' strings identifying the type of the Client
               Print Support Files.  Valid values are: 'printer-
               driver', 'ppd', 'updf', 'gpd'.

"file-name"    One REQUIRED CASE-SENSITIVE string identifying the name
               by which the Client Print Support Files will be
               installed on the workstation.  For Client Print Support
               Files of type 'printer-driver', this is also the name
               that identifies this printer driver in an .inf file.

"policy"       One REQUIRED LOWER-CASE 'keyword' string indicating the
               policy for automatic loading.  Values:  'unknown',
               'manufacturer-recommended', 'administrator-recommended',
               'manufacturer-experimental,  and 'administrator-
               experimental'.  The experimental values are for beta
               test.

"file-size"    One OPTIONAL file size in octets represented as ASCII
               decimal digits.

"file-         One OPTIONAL LOWER-CASE version number.  Recommended to
version"       be of the form "Major.minor[.revision]" "Major" is the
               major version number, "minor" is the minor version
               number and "revision" is an optional revision number.

"file-date-    One OPTIONAL File CASE-SENSITIVE creation date and time
time"          according to ISO 8601 where all fields are fixed length
               with leading zeroes (see [RFC2518] Appendix 2).
               Examples:  2000-01-01T23:09:05Z and 2000-01-01T02:59:59-
               04.00


Each value MUST refer to one and only one set of Client Print Support
Files, even if the files are downloadable from various repositories
(i.e., even if they are associated with multiple URIs).

The following illustrates what two valid values of the "client-print-
support-files-supported" (1setOf octetString(MAX)) Printer Description
attribute might look like:

     uri=ipp://mycompany.com/myprinter<
     os-type=windows-95< cpu-type=x86-32<
     document-format=application/postscript<
     natural-language=en< compression=gzip<
     install-file-type=printer-driver<
     install-file-name=CompanyX-ModelY-driver.gz<
     policy=manufacturer-recommended<




Parra, Tronson, Hastings                                       [page 8]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


     uri=ftp://mycompany.com/root/drivers/win95/CompanyX/ModelY.g
     z<
     os-type=windows-95< cpu-type=x86-32<
     document-format=application/postscript,application/vnd.hp-
     PCL<
     natural-language=en,fr< compression=gzip<
     install-file-type=printer-driver<
     install-file-name=Company T Model Z driver.gz<
     policy=manufacturer-recommended<

The above examples have been broken onto separate lines for readability
in this document.  However, there MUST NOT be any line breaks in the
actual values.


The "client-print-support-files-supported" Printer Description attribute
MAY be preset at manufacturing time or set via the IPP Set-Printer-
Attribute operation or through administrative means outside the scope of
IPP.


3.2 Get-Printer-Attributes Operation Extension


The "client-print-support-files-supported" Printer Description attribute
defined in section 3.1 contains information, such as operating system,
natural language, and document format, about all of the sets of Client
Print Support Files.  This section defines an extension to the Get-
Printer-Attributes operation that allows a workstation to filter out all
but the Client Print Support Files of interest.


3.2.1Get-Printer-Attributes Request

A Printer MAY contain information about multiple sets of Client Print
Support Files to match the different operating systems, natural
languages and document formats it supports.  A workstation may query
this information by including the 'client-print-support-files-supported'
keyword as a value of the "requested-attributes" operation attribute of
the Get-Printer-Attributes operation.


3.2.1.1   client-print-support-files-filter (octetString(MAX)) operation
      attribute

The client can request a subset of the values of the "client-print-
support-files-supported" Printer attribute by supplying the "client-
print-support-files-filter" (octetString(MAX)) operation attribute in
the request as a filter.  The filter value indicates in which Client
Print Support Files the client is interested. The client MAY supply this
attribute.  The Printer MUST support this attribute.

The filter value of the "client-print-support-files-filter" attribute is
a composite string with the same format as that of "client-print-
support-files-supported" (see Table 1 - "client-print-support-files-


Parra, Tronson, Hastings                                       [page 9]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


supported" attribute fields in section 3.1) with the following
exceptions:


     Table 2 - "client-print-support-files-filter" attribute fields

     Field     Field Value in the "client-print-support-files-filter"
     Name      attribute


     uri-      One or more REQUIRED comma-separated LOWER-CASE
     scheme    'uriScheme' string values identifying the uri scheme to be
               filtered on.  Example URI schemes are: ftp, http, and ipp.
               The Printer SHOULD support the ipp scheme.  If supplied by
               the client, this field NEED NOT be first.  If this field
               is omitted by the client, the Printer returns all schemes.


     xxx       All of the fields in "Table 1 - "client-print-support-
               files-supported" attribute fields, with the single
               exception of the "uri" field which a client MUST NOT
               supply and a Printer MUST NOT support.


               Any field can have more than one value separated by a
               COMMA (,), including the fields that Table 1 indicates
               MUST BE single valued.





Clients MAY supply additional fields and/or additional values of defined
fields.


The Printer returns only the values of the "client-print-support-files-
supported" Printer Description attribute that match the filter in the
"client-print-support-files-filter" operation attribute. A match occurs
if at least one value of each field supplied in the filter matches a
Client Print Support File value.  A match for a CASE-INSENSITIVE field
occurs independent of the case of the letters supplied by the client and
those stored by the Printer, while a match for a LOWER-CASE field is a
strict character for character match.


The following are two examples of a "client-print-support-files-filter"
filter value:

     os-type=windows-95< cpu-type=x86-32<
     document-format=application-postscript< natural-language=en,de<

     uri-scheme=ipp< os-type=windows-95< cpu-type=x86-32<
     document-format=application-postscript< natural-language=en,de<


See section 3.2.2 for example matching in the response.


Parra, Tronson, Hastings                                      [page 10]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


The IPP Printer is REQUIRED to support this operation attribute and the
following member fields in a "client-print-support-files-filter"
operation attribute filter in the Get-Printer-Attributes request:

  1. uri-scheme
  2. os-type
  3. cpu-type
  4. document-format
  5. natural-language

Printer implementations MAY support additional fields and additional
values of defined fields.  Printers MUST ignore fields they do not
support.


If the "client-print-support-files-filter" operation attribute filter is
not supplied by the client, the printer should behave as if the
attribute had been provided with all fields left empty (i.e., return an
unfiltered list).


It is RECOMMENDED that workstations first use the Get-Printer-Attributes
operation in combination with "client-print-support-files-filter"
operation attribute filter to get a list of the potential Client Print
Support Files that meet the workstation's requirements.  The workstation
can then choose from the returned list which Client Print Support Files
to use and where to get them.  If one of the URIs returned is an IPP
uri, the workstation can retrieve the Client Print Support Files from an
IPP printer via the Get-Client-Print-Support-Files operation (see
section 3.3).



3.2.2Get-Printer-Attributes Response


A Printer MUST return the "client-print-support-files-supported" (1setOf
octetString(MAX)) attribute in the Printer Object Attributes group
(group 3) when requested by a client.  Each returned attribute value
must satisfy the criteria specified by the client in the request.


For example, if the request contains the following "client-print-
support-files-filter" filter:

     os-type=windows-95< cpu-type=x86-32< document-format=application-
     postscript<
     natural-language=en,de<

A conforming response is the following two octet String values:

     uri=ipp://mycompany.com/myprinter<
     os-type=windows-95< cpu-type=x86-32<
     document-format=application/postscript<
     natural-language=en< compression=gzip<
     install-file-type=printer-driver<
     install-file-name=CompanyX-ModelY-driver.gz<


Parra, Tronson, Hastings                                      [page 11]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


     policy=manufacturer-recommended<

     uri=ftp://mycompany.com/root/drivers/win95/CompanyX/ModelY.g
     z<
     os-type=windows-95< cpu-type=x86-32<
     document-format=application/postscript,application/vnd.hp-
     PCL<
     natural-language=en,fr< compression=gzip<
     install-file-type=printer-driver<
     install-file-name=CompanyX-ModelY-driver.gz<
     policy=manufacturer-recommended<

These examples have been broken onto separate lines for readability in
this document.  However, there MUST NOT be any line breaks in the actual
values.


As an other example, if the above request had also contained the "uri-
scheme" field in the following "client-print-support-files-filter"
filter:

     uri-scheme=ipp< os-type=windows-95< cpu-type=x86-32<
     document-format=application-postscript<
     natural-language=en,de<

Then only the first value would have been returned as a single
octetString value:

     uri=ipp://mycompany.com/myprinter<
     os-type=windows-95< cpu-type=x86-32<
     document-format=application/postscript<
     natural-language=en< compression=gzip<
     install-file-type=printer-driver<
     install-file-name=CompanyX-ModelY-driver.gz<
     policy=manufacturer-recommended<

3.3 Get-Client-Print-Support-Files


This RECOMMENDED operation allows a client to download Client Print
Support Files from an IPP Printer.


3.3.1Get-Client-Print-Support-Files Request


The following sets of attributes are part of the Get-Client-Print-
Support-Files request:


Group 1: Operation Attributes

     Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in [RFC2911], section 3.1.4.1.



Parra, Tronson, Hastings                                      [page 12]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


     Target:
        The "printer-uri" (uri) operation attribute which is the target
        for this operation as described in [RFC2911], section 3.1.5.

     Requesting User Name:
        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the client as described in [RFC2911], section 8.3.

     "client-print-support-files-uri" (uri):
        The client MUST supply this attribute specifying the uri for the
        desired Client Print Support Files, i.e., the value of the "uri"
        field returned by the Get-Printer-Attributes in one of the
        values of the "client-print-support-files-supported" (1setOf
        octetString(MAX)) Printer attribute.  The URI scheme must be
        ipp.

        Note:  This uri is neither the Printer.s target "printer-uri"
        nor the URI in the HTTP header.


3.3.2Get-Client-Print-Support-Files Response


The Printer object returns the following sets of attributes as part of
the Get-Client-Print-Support-Files Response:


Group 1: Operation Attributes

     Status Message:
        In addition to the REQUIRED status code returned in every
        response, the response OPTIONALLY includes a "status-message"
        (text(255)) operation attribute as described in [RFC2911],
        sections 13 and 3.1.6.

     Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in [RFC2911], section 3.1.4.2.

Group 2: Unsupported Attributes
     See [RFC2911], section 3.1.7 for details on returning Unsupported
     Attributes.

Group 3: Printer Object Attributes
     "client-print-support-files-supported" (octetString(MAX)).
        This attribute identifies the properties of the returned Client
        Print Support Files.  The Printer object MUST return this
        attribute if the response includes Group 4 (i.e., if a set of
        Client Print Support Files identified by the supplied "client-
        support-files-uri" was found).  The Printer MUST return the
        format shown in section 3.1.

Group 4: Client Print Support Files



Parra, Tronson, Hastings                                      [page 13]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


     The printer MUST supply the Client Print Support Files that match
     the client's criteria following the "end-of-attributes" tag.  All
     necessary files must be compressed into a single file.


4  Conformance

A Printer conforming to this specification:

  1. MUST support the "client-print-support-files-supported" Printer
     Description attribute as defined in section 3.1, including all of
     the REQUIRED fields defined in Table 1 and MAY support the OPTIONAL
     fields defined in Table 1.

  2. MUST support the "client-print-support-files-filter" operation
     attribute in the Get-Printer-Attributes request as defined in
     section 3.2, including all of the fields defined in Table 2 and
     ignoring any fields not recognized.

  3. MUST support at least one of the following URI schemes that
     identify the support files:  ftp, http, or ipp, of which the ipp
     scheme is the RECOMMENDED one.

  4. SHOULD support the Get-Client-Print-Support-Files operation as
     described in section 3.3.  If this operation is supported, then one
     of the supported schemes MUST be ipp.

A client conforming to this specification:

  1. MUST ignore any fields returned by the Printer in the "client-
     print-support-files-supported" Printer Description attribute that
     the client does not recognize or support.

  2. SHOULD be able to retrieve Client Print Support Files by either ftp
     Get or http Get operations.

  3. MUST be able to retrieve Client Print Support Files using the Get-
     Client-Print-Support-Files operation, i.e., support the ipp scheme.


5  Encoding of the Operation Layer

This extension uses the operation layer encoding described in [RFC2910].


6  Encoding of Transport Layer

This specification uses the transport layer encoding described in
[RFC2910] with the following extensions.

New Error codes:

     0x0417    client-error-client-print-support-file-not-found

New Operation code


Parra, Tronson, Hastings                                      [page 14]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


     0x0021    Get-Client-Print-Support-Files


7  IANA Considerations

The IANA-registered operating system names that IANA has registered [os-
names] are required by this spec.

The "cpu-type" is not a current IANA registry.  The current IANA machine
registration [cpu-names] is really a machine model number, not a CPU
type.  Also whether a CPU is 16-bit, 32-bit, or 64-bit needs to be
indicated in the CPU name which is not currently reflected in the IANA
CPU registry.  Therefore, the os-type will be a new type of registration
with initial values assigned in Table 1 under "os-type", as with other
elements in IPP [see RFC2911 section 6 and 11].

All other IANA considerations are already addressed by IPP.


8  Internationalization Considerations

All text representations introduced by this specification adhere to the
internationalization-friendly representation supported by IPP.  This
work is also accommodates the use of Client Print Support Files of
different languages.


9  Security Considerations

The IPP Model and Semantics document [RFC2911] discusses high-level
security requirements (Client Authentication, Server Authentication and
Operation Privacy). Client Authentication is the mechanism by which the
client proves its identity to the server in a secure manner. Server
Authentication is the mechanism by which the server proves its identity
to the client in a secure manner. Operation Privacy is defined as a
mechanism for protecting operations from eavesdropping.

Only operators of a printer should be allowed to set the "printer-
driver-supported" attribute and only users of the printer should be
allowed to query that information.

Printers that support the Get-Client-Print-Support-Files operation are
REQUIRED to implement TLS to enable users to reliably authenticate the
source of the Client Print Support Files.


10 References


[cpu-names]
     IANA Registry of CPU Names at ftp://ftp.isi.edu/in-
     notes/iana/assignments/XXX.

[os-names]
     IANA Registry of Operating System Names at ftp://ftp.isi.edu/in-
     notes/iana/assignments/operating-system-names.


Parra, Tronson, Hastings                                      [page 15]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


[RFC2026]
     S. Bradner, "The Internet Standards Process -- Revision 3", RFC
     2026, October 1996.

[RFC2518]
     Goland, Y., et al, "HTTP Extensions for Distributed Authoring --
     WEBDAV", RFC 2518, February 1999.

[RFC2616]
     R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P.
     Leach, T. Berners-Lee, "Hypertext Transfer Protocol - HTTP/1.1",
     RFC 2616, June 1999.

[RFC2911]
     R. deBry, T. Hastings, R. Herriot, S. Isaacson, P. Powell,
     "Internet Printing Protocol/1.0: Model and Semantics", <draft-ietf-
     ipp-model-v11-06.txt>, March 1, 2000.

[RFC2910]
     Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing
     Protocol/1.1: Encoding and Transport", draft-ietf-ipp-protocol-v11-
     05.txt, March 1, 2000.


11 Author's Addresses

     Hugo Parra
     Novell, Inc.
     1800 South Novell Place
     Provo, UT   84606

     Phone: 801-861-3307
     Fax:   801-861-4025
     e-mail: hparra@novell.com

     Ted Tronson
     Novell, Inc.
     1800 South Novell Place
     Provo, UT   84606

     Phone: 801-861-3338
     Fax:   801-861-4025
     e-mail: ttronson@novell.com

     Thomas N. Hastings
     Xerox Corp.
     737 Hawaii St.  ESAE 231
     El Segundo, CA   90245

     Phone: 310-333-6413
     Fax:   310-333-5514
     e-mail: hastings@cp10.es.xerox.com



Parra, Tronson, Hastings                                      [page 16]


                         Expires May 7, 2001



INTERNET-DRAFT   IPP: Printer Installation Extension  November 7, 2000


12 Full Copyright Statement

Copyright (C) The Internet Society (2000). 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.






























Parra, Tronson, Hastings                                      [page 17]

                         Expires May 7, 2001