INTERNET-DRAFT

                                                 Robert Herriot (editor)
                                                        Sun Microsystems
                                                           Sylvan Butler
                                                         Hewlett-Packard
                                                              Paul Moore
                                                              Microsoft.
                                                            Randy Turner
                                                              Sharp Labs
                                                           July 30,
                                                        October 23, 1997

         Internet Printing Protocol/1.0: Protocol Specification
                     draft-ietf-ipp-protocol-01.txt
                     draft-ietf-ipp-protocol-02.txt

Status of this Memo

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

Internet-Drafts are draft documents valid for a maximum of six months
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To learn the current status of any Internet-Draft, please check the
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ftp.isi.edu (US West Coast).

Abstract

This document is one of a set of documents, which together describe all
aspects of a new Internet Printing Protocol (IPP).  IPP is an
application level protocol that can be used for distributed printing
using Internet tools and technology.  The protocol is heavily influenced
by the printing model introduced in the Document Printing Application
(ISO/IEC 10175 DPA) standard. standard [dpa].  Although DPA specifies both end
user and administrative features, IPP version 1.0 is focused only on end
user functionality.

The full set of IPP documents includes:

  Internet Printing Protocol: Requirements
  Internet Printing Protocol/1.0: Model and Semantics
  Internet Printing Protocol/1.0: Security
  Internet Printing Protocol/1.0: Protocol Specification
  Internet Printing Protocol/1.0: Directory Schema

The requirements 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
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users, operators, and administrators.  The requirements document calls
out a subset of end user requirements that MUST be satisfied in the
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first version of IPP.  Operator and administrator requirements are out
of scope for v1.0. The model and semantics document describes a
simplified model with abstract objects, their attributes, and their
operations. The model introduces a Printer object and a Job object.  The
Job object supports multiple documents per job. The security document
covers potential threats and proposed counters to those threats.  The protocol
specification is formal document which incorporates the ideas in all the
other documents into a concrete mapping using clearly defined data
representations and transport protocol mappings that real implementers
can use to develop interoperable client and server printer (server) side
components. Finally, the directory schema document shows a generic
schema for directory service entries that represent instances of IPP
Printers.

This document is the "Internet ''Internet Printing Protocol/1.0: Protocol
Specification"
Specification'' document.

Notice

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FITNESS FOR A PARTICULAR PURPOSE.

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                           Table of Contents

1. Introduction........................................................4
2. Conformance Terminology.............................................4
3. Encoding of  the Operation Layer....................................4
   3.1 Picture of the Encoding.........................................5
   3.2 Syntax of Encoding..............................................7 Encoding..............................................6
   3.3 Version.........................................................8
   3.4 Mapping of Operations...........................................8
   3.5 Mapping of Status-code..........................................8
   3.6 Tags............................................................9 Tags.............................................................   8
      3.6.1 Delimiter Tags.............................................9 Tags.............................................8
      3.6.2 Value Tags................................................10 Tags.................................................9
   3.7 Name-Lengths...................................................11
   3.8 Mapping of Parameter Names.....................................11 Attribute  Names....................................11
   3.9 Value Lengths..................................................13 Lengths..................................................12
   3.10 Mapping of Attribute and Parameter Values.....................13 Values...................................13
   3.11 Data..........................................................14 Data............................................................   15
4. Encoding of Transport Layer........................................14 Layer........................................15
   4.1 General Headers................................................15 Headers................................................16
   4.2 Request  Headers...............................................16  Headers...............................................17
   4.3 Response Headers...............................................17 Headers...............................................18
   4.4 Entity  Headers................................................17  Headers................................................18
5. Security Considerations............................................18 Considerations............................................19
6. References.........................................................19 References.........................................................20
7. Author's Address...................................................20 Address...................................................21
8. Other Participants:................................................20 Participants:................................................22
9. Appendix A: Protocol Examples......................................21 Examples......................................22
   9.1 Print-Job Request..............................................21 Request..............................................22
   9.2 Print-Job Response (successful)................................21 (successful)................................23
   9.3 Print-Job Response (failure)...................................22 (failure)...................................24
   9.4 Print-URI Request..............................................23 Request..............................................25
   9.5 Create-Job Request.............................................23 Request.............................................26
   9.6 Get-Jobs Request...............................................23 Request...............................................26
   9.7 Get-Jobs Response..............................................24 Response..............................................27
10. Appendix B: Mapping of Each Operation in the Encoding.............25 Encoding.............28
11. Appendix C: Hints to implementors using IPP with SSL3.............32

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1. Introduction

This document contains the rules for encoding IPP operations and
describes two layers: the transport layer and the operation layer.

The transport layer consists of an  HTTP/1.1 request or response. RFC
2068 [27] [r2068] describes HTTP/1.1. This document specifies the HTTP
headers that an IPP implementation supports.

The operation layer consists of  a message body in an HTTP request or
response.  The document "Internet Printing Protocol/1.0: Model and
Semantics" [21] [ipp-m] defines the semantics of such a message body and the
supported values. This document specifies the encoding of an IPP
operation. The aforementioned document [21] [ipp-m] is henceforth referred to
as the "IPP model document"

2. Conformance Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and  "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [25]. [r2119].

3. Encoding of  the Operation Layer

The operation layer SHALL contain a single operation request or
operation response.

The encoding consists of octet octets as the most primitive type. There are
several types built from octets, but two important  types are integers
and characters, on which most  other data types are built. Every
character in this encoding SHALL be a member of the UCS-2 coded
character set and SHALL be encoded using UTF-8 which uses 1 to 3 octets
per character. Every integer in this encoding SHALL be encoded as a
signed integer using two's-complement binary encoding with big-endian
format (also known as "network order" and "most significant byte
first"). The number of octets for an integer SHALL be 1, 2 or 4,
depending on usage in the protocol. Such one-octet integers, henceforth
called SIGNED-BYTE, are used for the version and tag fields. Such two-
byte integers, henceforth called SIGNED-SHORT are used for the
operation, status-code and length fields. Four byte integers, henceforth
called SIGNED-INTEGER, are used for values fields.

The following two sections present the operation layer in two ways

  .  informally through pictures and description
  .  formally through Augmented Backus-Naur Form (ABNF), as specified by
     draft-ietf-drums-abnf-02.txt [29] [abnf]

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3.1 Picture of the Encoding

The encoding for an operation request or response consists of:

  -----------------------------------------------
  |                    version                  |   2 bytes  - required
  -----------------------------------------------
  |operation (request) or status-code (response)|   2 bytes  - required
  -----------------------------------------------------------
  |                 parameter-tag               |   1 byte  |
  -----------------------------------------------           |- optional
  |               parameter-sequence            |   m bytes |
  -----------------------------------------------------------
  |                 attribute-tag               xxx-attributes-tag            |   1 byte  |
  -----------------------------------------------           |-0 or more
  |               attribute-sequence             xxx-attribute-sequence          |   n bytes |
  -----------------------------------------------------------
  |                  data-tag                   |   1 byte   - required
  -----------------------------------------------
  |                     data                    |   q bytes  - optional
  -----------------------------------------------

The parameter-tag xxx-attributes-tag and parameter-sequence may be omitted if the operation
has no parameters. xxx-attribute-sequence represents four
different values of "xxx", namely, operation, job, printer and
unsupported-job. The attribute-tag xxx-attributes-tag and attribute-sequence xxx-attribute-sequence may
be omitted if the operation has no attributes or it may be replicated for
an operation repeated with
the same or different values of "xxx" in ways that contains attributes for multiple objects. are specific to each
operation. The data is omitted from some operations, but the data-tag is
present even when the data is omitted. Note, the parameter-tag, attribute-tag xxx-attributestags and
data-tag are called `delimiter-tags'.

A parameter-sequence consists

Note: the xxx-attribute-sequence, shown above may consist of  a sequence 0 bytes,
according to the rule below.

An xxx-attributes-sequence consists of zero or more compound-
parameters.

  -----------------------------------------------
  |               compound-parameter            |   r bytes - 0 or more
  -----------------------------------------------

An attributes-sequence consists of zero or more compound-attributes. compound-attributes.

  -----------------------------------------------
  |              compound-attribute             |   s bytes - 0 or more
  -----------------------------------------------

A compound-parameter compound-attribute consists of a parameter an attribute with a single value
optionally followed
by zero or more additional values. A compound-
attribute consists an attribute with

Note: a `compound-attribute' represents a single value followed by zero attribute in the model
document.  The `additional value' syntax is for attributes with 2 or
more additional values.

Each parameter or attribute consists of:

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  -----------------------------------------------
  |                   value-tag                 |   1 byte
  -----------------------------------------------
  |               name-length  (value is u)     |   2 bytes
  -----------------------------------------------
  |                     name                    |   u bytes
  -----------------------------------------------
  |              value-length  (value is v)     |   2 bytes
  -----------------------------------------------
  |                     value                   |   v bytes
  -----------------------------------------------

An additional value consists of:

  -----------------------------------------------------------
  |                   value-tag                 |   1 byte  |
  -----------------------------------------------           |
  |            name-length  (value is 0x0000)   |   2 bytes |
  -----------------------------------------------           |-0 or more
  |              value-length (value is w)      |   2 bytes |
  -----------------------------------------------           |
  |                     value                   |   w bytes |
  -----------------------------------------------------------

Note: an additional value is like a parameter or an attribute whose name-
length name-length is 0.

From the standpoint of a parsing loop, the encoding consists of:

  -----------------------------------------------
  |                    version                  |   2 bytes  - required
  -----------------------------------------------
  |operation (request) or status-code (response)|   2 bytes  - required
  -----------------------------------------------------------
  |        tag (delimiter-tag or value-tag)     |   1 byte  |
  -----------------------------------------------           |-0 or more
  |           empty or rest of parameter/attribute attribute        |   x bytes |
  -----------------------------------------------------------
  |                   data-tag                  |   2 bytes  - required
  -----------------------------------------------
  |                     data                    |   y bytes  - optional
  -----------------------------------------------

The value of the tag determines whether the bytes following the tag are:

  .  parameters
  .  attributes
  .  data
  .  the remainder of a single parameter or attribute where the tag specifies the
     type of the value.

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3.2 Syntax of Encoding

The syntax below is ABNF [abnf] except `strings of literals' SHALL be
case sensitive. For example `a' means lower case  `a' and not upper case

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`A'.   In addition, SIGNED-BYTE and SIGNED-SHORT fields are represented
as `%x' values which show their range of values.

  ipp-message = ipp-request / ipp-response
  ipp-request = version operation
            [parameter-tag parameter-sequence ]
           *(attribute-tag  attribute-sequence)
           *(xxx-attributes-tag  xxx-attribute-sequence) data-tag data
  ipp-response = version status-code
            [parameter-tag parameter-sequence ]
           *(attribute-tag attribute-sequence)
           *(xxx-attributes-tag xxx-attribute-sequence)  data-tag  data
  xxx-attribute-sequence = *compound-attribute
       ; where "xxx" in the three rules above stands for any of the
  following
       ; values:  "operation",  "job", "printer" or "unsupported-job".

  version = major-version minor-version
  major-version = SIGNED-BYTE  ; initially %d1
  minor-version = SIGNED-BYTE  ; initially %d0

  operation = SIGNED-SHORT    ; mapping from model defined below
  status-code = SIGNED-SHORT  ; mapping from model defined below

  parameter-sequence = *compound-parameter
  attribute-sequence = *compound-attribute
  compound-parameter = parameter *additional-values

  compound-attribute = attribute *additional-values

  parameter = value-tag name-length name value-length value

  attribute = value-tag name-length name value-length value
  additional-values = value-tag zero-name-length value-length value

  name-length = SIGNED-SHORT    ; number of octets of `name'
  name = LALPHA *( LALPHA / DIGIT / "-" / "_" / "." )
  value-length = SIGNED-SHORT  ; number of octets of `value'
  value = OCTET-STRING

  data = OCTET-STRING

  zero-name-length = %x00.00  ; name-length of 0
  parameter-tag =
  operation-attributes-tag=  %x01            ; tag of 1
  attribute-tag
  job-attributes-tag     =  %x02             ; tag of 2
  printer-attributes-tag =  %x04             ; tag of 4
  unsupported-job-attributes-tag =  %x05     ; tag of 5
  data-tag = %x03                                              ; tag of
  3
  value-tag = %x10-FF

  SIGNED-BYTE = BYTE
  SIGNED-SHORT = 2BYTE
  DIGIT = %x30-39    ;  "0" to "9"
  LALPHA = %x61-7A   ;  "a" to "z"
  BYTE = %x00-FF
  OCTET-STRING = *BYTE

The syntax allows a parameter-tag an xxx-attributestag to be present when the parameter-
sequence xxx-
attribute-sequence that follows is empty. The same is true for the attribute-tag
and the attribute-sequence that follows. The syntax is defined this way

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to allow for the response of Get-Jobs where no attributes are returned
for some job-objects.  Although it is RECOMMENDED that the sender not
send a parameter-tag if there are no parameters and not send an
attribute-tag xxx-attributestag if there are no attributes (except in the Get-Jobs Get-

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Jobs response just mentioned), the receiver MUST be able to decode such
syntax.

3.3 Version

The version SHALL consist of a major and minor version, each of which
SHALL be represented by a SIGNED-BYTE. The protocol described in this
document SHALL have a major version of 1 (0x01) and a minor version of
0 (0x00).  The ABNF for these two bytes SHALL be %x01.00.

3.4 Mapping of Operations

The following SHALL be the mapping of operations names to integer values
which are encoded as a SIGNED-SHORT. The operations

Operations are defined as enums in the
IPP model document  The table below includes a range of values for
future extensions to the protocol and document. An operations
enum value SHALL be encoded as a separate range for private
extensions.  It is RECOMMENDED that SIGNED-SHORT

Note: the private extension values be used
for temporary experimental implementations and not for deployed
products.

   Encoding (hex) Operation

   0x0            reserved (not used)
   0x1            Get-Operations
   0x2            Print-Job
   0x3            Print-URI
   0x4            Validate-Job
   0x5            Create-Job
   0x6            Send-Document
   0x7            Send-URI
   0x8            Cancel-Job
   0x9            Get-Attributes
   0xA            Get-Jobs
   0xB-0x3FFF     reserved for future operations
   0x4000-0xFFFF 0x4000 to 0xFFFF are reserved for private extensions extensions.

3.5 Mapping of Status-code

The following SHALL be the mapping of status-code names to integer
values which are encoded as a SIGNED-SHORT. The status-code names

Status-codes are defined as enums in the IPP model document.

If an IPP A status-code is returned, then the HTTP
enum value SHALL be encoded as a SIGNED-SHORT

If an IPP status-code is returned, then the HTTP Status-Code MUST be 200
(OK). With any other HTTP Status-Code value, the HTTP response SHALL NOT
contain an IPP message-body, and thus no IPP status-code is returned.

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Note: the integer encodings below were chosen to be similar to
corresponding Status-Code values in HTTP. The IPP client and server
errors have the same relative offset to their base as corresponding HTTP
errors, but the IPP base is a multiple of 0x100 whereas the HTTP base is
a multiple of 100. Despite this similarity,  the Status-Code returned at
the HTTP level will always be different except in the case where `OK' is
returned at both levels, 200 (OK) in HTTP and 0 (successful-OK) in IPP.

Note: some status-code values, such as client-error-unauthorized, may
be returned at the transport (HTTP) level rather than the operation
level.

ISSUE: as implementations proceed, we will learn what error code need to
be supported at the IPP level.

   Encoding (hex)  Status-Code Name

   0               successful-OK
   0x400           client-error-bad-request
   0x401           client-error-unauthorized
   0x403           client-error-forbidden
   0x404           client-error-not-found
   0x405           client-error-method-not-allowed
   0x408           client-error-timeout
   0x40A           client-error-gone
   0x40D           client-error-request-entity-too-large
   0x40E           client-error-request-URI-too-long
   0x40F           client-error-unsupported-document-format
   0x410           client-error-attribute-not-supported
   0x500           server-error-internal-server-error
   0x501           server-error-operation-not-implemented
   0x503           server-error-service-unavailable
   0x504           server-error-timeout
   0x505           server-error-version-not-supported
   0x506           server-error-printer-error
   0x507           server-error-temporary-error

3.6 Tags

There are two kinds of tags:

  .  delimiter tags: delimit major sections of the protocol, namely
     parameters,
     attributes and data
  .  value tags: specify the type of each parameter or attribute value

3.6.1 Delimiter Tags

The following table specifies the values for the delimiter tags:

   Tag Value (Hex)    Delimiter

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   Tag Value (Hex)    Delimiter

   0x00               reserved
   0x01               parameter-tag               operation-attributes-tag
   0x02               attribute-tag               job-attributes-tag
   0x03               data-tag
   0x04-0x0F
   0x04               printer-attributes-tag
   0x05               unsupported-job-attributes-tag
   0x06-0x0F          reserved for future delimiters

3.6.2 Value Tags

The remaining tables show values for

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When an xxx-attributes-tag occurs in the value-tag, which is protocol, it SHALL mean that
the first
octet of  a parameter zero or attribute. The value-tag specifies more following attributes up to the type of next delimiter tag are
xxx attributes as defined in the value of model document, where xxx is operation,
job, printer, unsupported-job.

Doing substitution for xxx in the parameter or attribute. The value of above paragraph, this means the value-tag of a
parameter or attribute
following. When an operation-attributes-tag occurs in the protocol, it
SHALL either be a type value specified mean that the zero or more following attributes up to the next
delimiter tag are operation attributes as defined in the model document or document.
When an "out-of-band" value, such as "unsupported" job-attributes-tag occurs in the protocol, it SHALL mean that
the zero or
"default". If more following attributes up to the value next delimiter tag are
job attributes as defined in the model document. When an printer-
attributes-tag occurs in the protocol, it SHALL mean that the zero or
more following attributes up to the next delimiter tag are printer
attributes as defined in the model document. When an unsupported-job-
attributes-tag occurs in the protocol, it SHALL mean that the zero or
more following attributes up to the next delimiter tag are unsupported-
job attributes as defined in the model document.

Each of value-tag the  four xxx-attributes-tags defined above is OPTIONAL in an
operation and each SHALL occur at most once in an operation, except for
job-attributes-tag in a Get-Jobs response which may occur zero or more
times.  The data-tag SHALL occur exactly once in an operation.

If an operation contains an operations-attribute-tag, it SHALL be the
first tag delimiter.  The data-tag SHALL be the last tag delimiter.

The order and presence of delimiter tags for each operation request and
each operation response SHALL be that defined in the model document. For
further details, see Section 3.8 Mapping of Attribute  Names and
Appendix B: Mapping of Each Operation in the Encoding.

3.6.2 Value Tags

The remaining tables show values for the value-tag, which is the first
octet of  an attribute. The value-tag specifies the type of the value of
the attribute. The value of the value-tag of an attribute SHALL either
be a type value specified in the model document or an "out-of-band"
value, such as "unsupported" or parameter "default". If  the value of value-tag
for an attribute is not "out-of-band" and differs from the value type
specified by the model document, then a server printer receiving such a request
MAY reject it, and  a the attribute or just the value.  A client receiving such a
response MAY ignore the attribute or parameter.

The following table specifies just the "out-of-band" values for value.

If  ipp-attribute-fidelity is true and a printer rejects a value, it is
the value-
tag.

   Tag same as rejecting the attribute. If  ipp-attribute-fidelity is false
and a printer rejects a value, or it a client rejects a value, then it
is as if the attribute didn't have that value. If after rejecting
values, the attribute no longer has any values the attribute is
rejected.

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Note: the intent of the above rule is for servers to be able to
understand text and name values when they don't support the
naturalLanguage override for the value.

The following table specifies the "out-of-band" values for the value-
tag.

   Tag Value (Hex)  Meaning

   0x10             unsupported
   0x11             default
   0x12             no-value
   0x13-0x1F
   0x13             compoundValue
   0x14-0x1F        reserved for future "out-of-band" values.

The "unsupported" value SHALL be used in the attribute-sequence of an
error response for those attributes which the server printer does not support.
The "default" value is reserved for future use of setting value back to
their default value. The "no-value" value is used for the "no-value"
value in model, e.g. when a document-attribute is returned as a set of
values and an attribute has no specified value for one or more of the
documents. The "compoundValue"  SHALL be used to form a single value
from a collection of values, and its value is the number of members
forming the compound value, excluding the compoundValue.  For example, a
text value with a naturalLanguage override consists of 3 "values": a
compoundValue with value 2, a naturalLanguage value and a text value.

The following table specifies the integer values for the value-tag

   Tag Value (Hex)   Meaning

   0x20              reserved
   0x21              integer
   0x22              boolean
   0x23              enum
   0x24-0x2F         reserved for future integer types

NOTE: 0x20 is reserved for "generic integer" if should ever be needed.

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The following table specifies the octet-string octetString values for the value-tag

   Tag Value (Hex)   Meaning

   0x30              reserved              octetString with an  unspecified format
   0x31              dateTime
   0x32              resolution
   0x33-0x3F
   0x33              rangeOfInteger
   0x34              reserved for dictionary (in the future)
   0x35-0x3F         reserved for future octet-string octetString types

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The following table specifies the character-string values for the value-
tag

   Tag Value (Hex)   Meaning

   0x40              reserved
   0x41              text
   0x42              name
   0x43              language              reserved
   0x44              keyword
   0x45              uri
   0x46              uriScheme
   0x47-0x5F
   0x47              charSet
   0x48              naturalLanguage
   0x49              mediaType
   0x4A-0x5F         reserved for future character string types

NOTE: 0x40 is reserved for "generic character-string" if should ever be
needed.

The values 0x60-0xFF are reserved for future types. There are no values
allocated for private extensions. A new type must be registered via the
type 2 process.

Issue: should this be a type 1 process.

3.7 Name-Lengths

The name-length field SHALL consist of a SIGNED-SHORT. This field SHALL
specify the number of octets in the name field which follows the name-
length field, excluding the two bytes of the name-length field.

If a name-length field has a value of zero, the following name field
SHALL be empty, and the following value SHALL be treated as an
additional value for the preceding parameter. Within a parameter-
sequence, if two parameters have the same name, the first occurrence
SHALL be ignored. attribute. Within an attribute-sequence, attribute-
sequence, if two attributes have the same name, the first occurrence
SHALL be ignored. The zero-length name is the only mechanism for multi-valued parameters and multi-
valued attributes.

3.8 Mapping of Parameter Attribute  Names

Some parameters attributes are encoded in a special position.  These parameters attribute are:

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  .  "printer-uri": The target printer-uri of each printer object operation in the IPP
     model document SHALL be specified both as a parameter named
     "printer-uri" in the operation layer ,and outside of  the operation layer
     as the request-URI on the Request-Line at the HTTP level,. level.
  .  "job-uri": The job -uri target job-uri of each job object operation in the IPP model
     document SHALL be specified both as a parameter named "job -
     uri" in the operation layer ,and outside of  the operation layer as the
     request-URI on the Request-Line at the HTTP level,.
  . level.
  .   "document-content": The parameter attribute named "document-content" in the
     IPP model document SHALL become the "data" in the operation layer.

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  .  "status-code": The parameter attribute named "status-code" in the IPP model
     document SHALL become the "status-code" field in the operation
     layer response.

The remaining parameters are encoded in the parameter-sequence or model document arranges the
attribute-sequence.  The parameter-sequence is remaining attributes into groups for actual
each operation
parameters request and the attribute-sequence is for object attributes. Of the
parameters defined response. Each such group SHALL be
represented in the IPP model document, some represent protocol by an actual
operation parameters xxx-attribute-sequence preceded by the
appropriate xxx-attributes-tag (See the table below and others represent a collection Appendix B:
Mapping of object
attributes.

A parameter Each Operation in the IPP model document SHALL represent a collection of
object attributes if its name contains the word "attributes"
immediately preceded by a space; otherwise it SHALL represent an actual
operation parameter. Note, some actual operation parameters contain Encoding). In addition, the
word "attributes" preceded by a hyphen ("-").  They are not a collection order of attributes.

If a parameter in IPP model document represents an actual operation
parameter
these xxx-attributes-tags and is not xxx-attribute-sequences in a special position, it the protocol
SHALL be encoded in the
parameter-sequence using the text name of the parameter specified same as in the
IPP model document.

If a parameter in IPP model document represents a collection of object
attributes, document, but the order of attributes
within each xxx-attribute-sequence SHALL be encoded in the attribute-sequence
using the text names of the attributes specified in the IPP model
document. unspecified. The IPP table below
maps the model document specifies the members group name to xxx-attributes-sequence

Model Document Group           xxx-attributes-sequence

Operation Attributes           operations-attributes-sequence
Job Template Attributes        job-attributes-sequence
Job Object Attributes          job-attributes-sequence
Unsupported Attributes         unsupported-job-attributes-sequence
Requested Attributes (Get-     job-attributes-sequence
Attributes of such attribute
collections, but  does not require that all members job object)
Requested Attributes (Get-     printer-attributes-sequence
Attributes of a collection be
present printer object)
Document Content               in an operation.

If an operation contain attributes from exactly one object, there SHALL
be exactly one attribute-sequence. a special position as described above
ISSUE: coordinate this with the model document.

If an operation contains attributes from more than one job object (e.g.
Get-Jobs response), the attributes from each job object SHALL be in a
separate attribute-sequence, job-attribute-sequence, such that the attributes from the ith
job object are in the ith attribute-sequence. job-attribute-sequence. See  Section 10
"Appendix B: Mapping of Each Operation in the Encoding" for table
showing the application of the rules above.

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3.9 Value Lengths

Each parameter attribute value SHALL be preceded by a SIGNED-SHORT which SHALL
specify the number of octets in the value which follows this length,
exclusive of the two bytes specifying the length.

For any of the types represented by binary signed integers, the sender
MUST encode the value in exactly four octets..

For any of the types represented by character-strings, the sender MUST
encode the value with all the characters of the string and without any
padding characters.

If a value-tag contains an "out-of-band" value, such as "unsupported",
the value-length SHALL be 0 and the value empty " the value has no
meaning when the value-tag has an "out-of-band" value. If a server printer or
client receives an operation with a nonzero value-length in this case,
it SHALL ignore the value field.

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3.10 Mapping of Attribute and Parameter Values

The following SHALL be the mapping of attribute and parameter values to their IPP
encoding in the value field. The syntax types are defined in the IPP
model document.

   Syntax of        Encoding
   Attribute Value

   text             an octet string where each character whose charset and language is
                    that specified within the operation request or
                    response.
                    The attributes-charset attribute with a member value of
                    type `charset' MUST be in the UCS-2 coded character set operations-
                    attribute sequence unless the request or response
                    contains no attributes. It specifies the charset
                    for all text and is encoded
                    using UTF-8. name values of attributes.
                    The text is encoded in "network attributes-natural-language attribute with a
                    value of type `naturalLanguage' MUST be in the
                    operations-attribute sequence unless the request
                    or response contains no attributes. It specifies
                    the language for all text and name values of
                    attributes unless overridden.  The language can
                    be overridden on a per-object or a per-value
                    basis.
                    The language can be overridden on a per-object
                    basis only for a job-sequence within a Get-Jobs
                    response. If the attributes-natural-language
                    attribute is present within such a context, it
                    must have a value of type `naturalLanguage' and
                    it overrides the language for all text and name
                    attributes within the job-attributes sequence
                    containing it, but not for attributes in any
                    other xxx-attribute-sequence.
                    The language can be overridden on a per-value
                    basis by syntactically preceding the text or name
                    value by two values: a value of type
                    compoundValue whose value is 2 and a value of
                    type naturalLanguage whose value is the language
                    override. From a protocol syntax view, the
                    compoundValue, the naturalLanguage value and the
                    text or name value appear as three separate
                    values of a single attribute, but from a semantic
                    view, the Printer treats them as a single value
                    where the naturalLanguage value overrides the
                    language of the immediately following text or
                    name value in the attribute.  Any text or name
                    values in the same or other attributes are not
                    affected by the override.  If an attribute
                    consists of a single text or name value, the
                    language value turns it into an attribute with
                    two values from a syntactic view.
                    The text is encoded in "network byte order" with

Moore and Turner         Expires April 23, 1998
   Syntax of        Encoding
   Attribute Value

                    the first character in the text
                    (according to reading order) being text (according to
                    reading order) being the first character in the
                    encoding.
   name             same as text
   charset          an octet string of US-ASCII encoded characters
                    specified in RFC 2046 [r2046] and contained in
                    the IANA character-set Registry [iana] according
                    to the IANA procedures [char].
   naturalLanguage  an octet string of US-ASCII encoded characters
                    and with a syntax specified by RFC 1766 [r1766]
   mediaType        an octet string of US-ASCII encoded characters
                    defined by RFC 2046 [r2046] and registered
                    according to the procedures of RFC 2048 [r2048]
                    for identifying a document format.  The value MAY
                    include a charset parameter, depending on the
                    specification of the first
                    character Media Type in the encoding.
   name             same as text
   language         same as text but with a syntax specified by RFC
                    1766 IANA
                    Registry [iana]. Examples:
   keyword          same as text.          an octet string of US-ASCII encoded characters. .
                    Allowed text values are defined in the IPP model
                    document
   uri              same              as text specified by RFC 1630 [r1630]
   uriScheme        same as text keyword
   boolean          one binary octet where 0x00 is `false' and 0x01
                    is `true'
   integer          a SIGNED-INTEGER, defined previously as a signed
                    integer using two's-complement binary encoding in
                    four octets with big-endian format (also known as
                    "network order" and "most significant byte
                    first").
   enum             same as integer. Allowed integer values are
                    defined in the IPP model document
   compoundValue    has the same representation as an integer, but
                    with a different meaning. If the value of a
                    compoundValue is n, then the n following values
                    of the attribute form a single value.  For
                    example, if an attribute has 3 successive values:
                    compoundValue of 2, naturalLanuage of `fr-CA' and
                    name of `bete', then these three "values" form a
                    single value which is a name of  `bete' in
                    Canadian French.
   dateTime         eleven octets whose contents are defined by
                    "DateAndTime" in RFC 1903. 1903 [r1903]. Although RFC
                    1903 also

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   Syntax of        Encoding
   Attribute Value defines an eight octet format which
                    omits the time zone, a value of this type in the
                    IPP protocol MUST use the eleven octet format.
   resolution       nine octets consisting of  2 SIGNED-INTEGERs
                    followed by a SIGNED-BYTE. The values are the
                    same as those specified in draft-ietf-printmib-
                    mib-info-02.txt [30]. RFC 1759 (Printer MIB)
                    [r1759]. The first SIGNED-INTEGER contains the
                    value of prtMarkerAddressabilityXFeedDir. The

Moore and Turner         Expires April 23, 1998
   Syntax of        Encoding
   Attribute Value

                    second SIGNED-INTEGER contains the value of
                    prtMarkerAddressabilityFeedDir. The SIGNED-BYTE
                    contains the value of
                    prtMarkerAddressabilityUnit.  Note: the latter
                    value is either 3 (tenThousandsOfInches) or 4
                    (micrometers) and the addressability is in 10,000
                    units of measure. Thus the SIGNED-INTEGERS
                    represent integral values in either dots-per-inch
                    or dots-per-centimeter.
   rangeOf  integer Eight octets consisting of 2 SIGNED-INTEGERs. The
                    first SIGNED-INTEGERs contains the lowest value
                    of the range and the second SIGNED-INTEGERs
                    contains the highest value of the range
   1setOf  X        encoding according to the rules for a parameter an attribute
                    with more than more value.  Each value X is
                    encoded according to the rules for encoding its
                    type.
   rangeOf  X       same 1setOf  X where the number of values is 2.

The type of the value in the model document determines the encoding in
the value and the value of the value-tag.

3.11 Data

The data part SHALL include any data required by the operation

4. Encoding of Transport Layer

HTTP/1.1 shall be the transport layer for this protocol.

The operation layer has been designed with the assumption that the
transport layer contains the following information:

  .  the URI of the target job or printer operation
  .  the total length of the data in the operation layer, either as a
     single length or as a sequence of chunks each with a length.
  .  the client's language,
It is REQUIRED that a printer support HTTP over port 80, though a
printer may support HTTP over port 516 or some other port.  In addition,
a printer may have to support another port for secure connections.

Note: Consistent with RFC 2068 (HTTP/1.1), HTTP URI's for IPP implicitly
reference port 80. If a URI references some other port, the character-set and port number
must be explicitly specified in the transport
     encoding. URI.

Each HTTP operation shall use the POST method where the request-URI is
the object target of the operation, and where the "Content-Type" of the
message-body in each request and response shall be "application/ipp".
The message-body shall contain the operation layer and shall have the

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syntax described in section 3.2 "Syntax of Encoding". A client

Moore and Turner         Expires April 23, 1998

implementation SHALL adhere to the rules for a client described in RFC
2068.
2068 [r2068]. A server printer (server) implementation SHALL adhere the rules
for an origin server described in RFC 2068.In the following sections,
there are a tables of all HTTP headers which describe their use in an
IPP client or server.  The following is an explanation of each column in
these tables.

  .  the "header" column contains the name of a header
  .  the "request/client" column indicates whether a client sends the
     header.
  .  the "request/server" "request/ server" column indicates whether a server supports
     the header when received.
  .  the "response/server" "response/ server" column indicates whether a server sends the
     header.
  .  the "response /client" column indicates whether a client supports
     the header when received.
  .  the "values and conditions" column specifies the allowed header
     values and the conditions for the header to be present in a
     request/response.

The table for "request headers" does not have columns for responses, and
the table for "response headers" does not have columns for requests.

The following is an explanation of the values in the "request/client"
and "response/server" "response/ server" columns.

  .  must: the client or server MUST send the header,
  .  must-if: the client or server MUST send the header when the
     condition described in the "values and conditions" column is met,
  .  may: the client or server MAY send the header
  .  not: the client or server SHOULD NOT send the header. It is not
     relevant to an IPP implementation.

The following is an explanation of the values in the "response/client"
and "request/server" "request/ server" columns.

  .  must: the client or server MUST support the header,
  .  may: the client or server MAY support the header
  .  not: the client or server SHOULD NOT support the header. It is not
     relevant to an IPP implementation.

4.1 General Headers

The following is a table for the general headers.

ISSUE: an HTTP expert should review these tables for accuracy.

General-     Request         Response        Values and Conditions
Header

             Client   Server Server  Client

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General-     Request         Response        Values and Conditions
Header

             Client   Server Server  Client

Cache-       must     not    must    not     "no-cache" only
Control
Connection   must-if  must   must-   must    "close" only. Both
                             if              client and server
                                             SHOULD keep a
                                             connection for the
                                             duration of a sequence
                                             of operations. The
                                             client and server MUST
                                             include this header
                                             for the last operation
                                             in such a sequence.
Date         may      may    must    may     per RFC 1123 [9] [r1123]
Pragma`      must     not    must    not     "no-cache" only
Transfer-    must-if  must   must-   must    "chunked" only .
Encoding                     if              Header MUST be present
                                             if Content-Length is
                                             absent.
Upgrade      not      not    not     not
Via          not      not    not     not

4.2 Request  Headers

The following is a table for the request headers.

Request-Header   Client    Server  Request Values and Conditions

Accept           may       must    "application/ipp" only.  This
                                   value is the default if the
                                   client omits it
Accept-Charset   may       must    per IANA Character Set registry.
                                   ISSUE:   not       not      Charset information is this useful for IPP? within
                                   the application/ipp entity
Accept-Encoding  may       must    empty and per RFC 2068 [27] [r2068]
                                   and IANA registry for content-codings content-
                                   codings
Accept-Language  may       must    see RFC 1766 [26]. A server
                                   SHOULD honor language requested
                                   by returning the values status-
                                   message, job-state-message and
                                   printer-state-reason in one of
                                   requested languages.  not       not     . language information is within
                                   the application/ipp entity
Authorization    must-if   must    per RFC 2068. A client MUST send
                                   this header when it receives a
                                   401 "Unauthorized" response and
                                   does not receive a  "Proxy-
                                   Authenticate" header.

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Request-Header   Client    Server  Request Values and Conditions
From             not       not     per RFC 2068. Because RFC
                                   recommends sending this header
                                   only with the user's approval, it

Moore and Turner         Expires April 23, 1998

Request-Header   Client    Server  Request Values and Conditions

                                   is not very useful
Host             must      must    per RFC 2068
If-Match         not       not
If-Modified-     not       not
Since
If-None-Match    not       not
If-Range         not       not
If-Unmodified-   not       not
Since
Max-Forwards     not       not
Proxy-           must-if   not     per RFC 2068. A client MUST send
Authorization                      this header when it receives a
                                   401 "Unauthorized" response and a
                                   "Proxy-Authenticate" header.
Range            not       not
Referer          not       not
User-Agent       not       not

4.3 Response Headers

The following is a table for the request headers.

Response-      Server  Client   Response Values and Conditions
Header

Accept-Ranges  not     not
Age            not     not
Location       must-if may      per RFC 2068. When URI needs
                                redirection.
Proxy-         not     must     per RFC 2068
Authenticate
Public         may     may      per RFC 2068
Retry-After    may     may      per RFC 2068
Server         not     not
Vary           not     not
Warning        may     may      per RFC 2068
WWW-           must-if must     per RFC 2068. When a server needs to
Authenticate                    authenticate a client.

4.4 Entity  Headers

The following is a table for the entity headers.

Entity-Header  Request         Response        Values and Conditions

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               Client  Server  Server   Client

Allow          not     not     not      not

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Entity-Header  Request         Response        Values and Conditions

               Client  Server  Server   Client

Content-Base   not     not     not      not
Content-       may     must    must     must   per RFC 2068 and IANA
Encoding                                       registry for content
                                               codings.
Content-       may     must    must     must   see RFC 1766 [26].       not     not     not      not    Application/ipp
Language                                       handles language
Content-       must-if must    must-if  must   the length of the
Length                                         message-body per RFC
                                               2068. Header MUST be
                                               present if Transfer-
                                               Encoding is absent..
Content-       not     not     not      not
Location
Content-MD5    may     may     may      may    per RFC 2068
Content-Range  not     not     not      not
Content-Type   must    must    must     must   "application/ipp"
                                               only
ETag           not     not     not      not
Expires        not     not     not      not
Last-Modified  not     not     not      not

5. Security Considerations

When utilizing HTTP 1.1 as a transport of IPP, the security
considerations outlined in RFC 2068 [r2068] apply.  Specifically, IPP
servers can generate a 401 "Unauthorized" response code to request
client authentication and IPP clients should correctly respond with the
proper "Authorization" header.  Both Basic Authentication (RFC 2068) and
Digest Authentication (RFC 2069) [r2069] flavors of authentication should SHALL
be supported.  The server chooses which type(s) of authentication to
accept.  Digest Authentication is a more secure method, and is always
preferred to Basic Authentication.

For secure communication (privacy in particular), IPP should SHOULD be run
using a secure communications channel.  Both For this purpose it is the
intention to define standardization of IPP in combination with Transport
Layer Security - (TLS), currently under development in the IETF, when the
TLS (draft-ietf-tls-protocol-03) specifications are agreed and IPSec (RFC 1825) provide necessary
features on the IETF standards track.

As an intercept solution for security. secure communication, the Secure Socket
Layer 3.0  (SSL3) could be used, but be warned that such implementations
may not be able to interoperate with a future standardized IPP and TLS
solution.  Appendix C gives some hints to implementors wanting to use
SSL3 as intercept solution.

It is possible to combine the two techniques, HTTP 1.1 client authentication
(either basic or digest) with a secure communications channel (either TLS or IPSec). channel.  Together

Moore and Turner         Expires April 23, 1998

the two are more secure than client authentication and they perform user
authentication.

Complete

See further discussion of IPP security considerations can be found concepts in the
IPP  Security model document

ISSUE: how does each security mechanism supply the job-originating-user
and job-originating-host values?

Moore and Turner        Expires January 30, 1998
[ipp-m].

6. References

[1]  Smith, R., Wright, F., Hastings, T., Zilles, S., and Gyllenskog,
     J., "Printer MIB", RFC 1759, March 1995.

[2]  Berners-Lee, T, Fielding, R., and Nielsen, H., "Hypertext Transfer
     Protocol - HTTP/1.0", RFC 1945, August 1995.

[3]

[822]     Crocker, D., "Standard for the Format of ARPA Internet Text
     Messages", RFC 822, August 1982.

[4]  Postel, J., "Instructions to RFC Authors", RFC 1543, October 1993.

[5]  ISO/IEC 10175 Document Printing Application (DPA), June 1996.

[6]  Herriot, R. (editor), X/Open A Printing System Interoperability
     Specification (PSIS), August 1995.

[7]  Kirk, M. (editor), POSIX System Administration - Part 4: Printing
     Interfaces, POSIX 1387.4 D8, 1994.

[8]  Borenstein, N., and Freed, N., "MIME (Multi-purpose Internet Mail
     Extensions) Part One: Mechanism for Specifying and Describing the
     Format of Internet Message Bodies", RFC 1521, September, 1993.

[9]

[r1123]   Braden, S., "Requirements for Internet Hosts - Application and
     Support", RFC 1123, October, 1989,

[10]

[r1179]   McLaughlin, L. III, (editor), "Line Printer Daemon Protocol"
     RFC
     1179, August 1990.

[11] 1179, August 1990.

[r1630]   T. Berners-Lee, "Universal Resource Identifiers in WWW: A
     Unifying Syntax for the Expression of  Names and Addresses of
     Objects on the Network as used in the Word-Wide Web", RFC 1630,
     June 1994.

[r1759]   Smith, R., Wright, F., Hastings, T., Zilles, S., and
     Gyllenskog, J., "Printer MIB", RFC 1759, March 1995.

[r1738]   Berners-Lee, T., Masinter, L., McCahill, M. , "Uniform
     Resource Locators (URL)", RFC 1738, December, 1994.

[20] Wright, F. D., "Requirements for an Internet Printing Protocol:"

[21] Isaacson, S, deBry, R, Hasting, T, Herriot, R, Powell, P, "Internet
     Printing Protocol/1.0: Model and Semantics"

[22] Internet Printing Protocol/1.0: Security

[23] Herriot, R, Butler, S, Moore, P, Turner, R, "Internet Printing
     Protocol/1.0: Protocol Specification"  (This document)

[24] Carter, K, Isaacson, S, "Internet Printing Protocol/1.0: Directory
     Schema"

[25] S. Bradner, "Key words for use in RFCs

[r1543]   Postel, J., "Instructions to Indicate Requirement
     Levels", RFC 2119 , March 1997

[26] Authors", RFC 1543, October
     1993.

[r1766]   H. Alvestrand, " Tags for the Identification of Languages",
     RFC 1766, March 1995.

Moore and Turner        Expires January 30, 1998

[27]       R Fielding, et al, "Hypertext Transfer Protocol " HTTP/1.1"
     RFC 2068, January 1997

[28]

[r1903}   J. Case, et al. "Textual Conventions for Version 2 of the
     Simple Network Managment Protocol (SNMPv2)", RFC 1903, January
     1996.

[29]

[r2046]   N. Freed & N. Borenstein, Multipurpose Internet Mail
     Extensions (MIME) Part Two: Media Types. November 1996. (Obsoletes
     RFC1521, RFC1522, RFC1590), RFC 2046.

[r2048]   N. Freed, J. Klensin & J. Postel.  Multipurpose Internet Mail
     Extension (MIME) Part Four: Registration Procedures. November 1996.
     (Format: TXT=45033 bytes) (Obsoletes RFC1521, RFC1522, RFC1590)
     (Also BCP0013), RFC 2048.

[r2068]   R Fielding, et al, "Hypertext Transfer Protocol " HTTP/1.1"
     RFC 2068, January 1997

[r2069]   J. Franks, et al, "An Extension to HTTP: Digest Access
     Authentication" RFC 2069, January 1997

Moore and Turner         Expires April 23, 1998

[r2119]   S. Bradner, "Key words for use in RFCs to Indicate Requirement
     Levels", RFC 2119 , March 1997

[r2184]   N. Freed, K. Moore, "MIME Parameter Value and Encoded Word
     Extensions: Character Sets, Languages, and Continuations", RFC
     2184, August 1997,

[abnf]    D. Crocker et al., "Augmented BNF for Syntax Specifications:
     ABNF",
     draft-ietf-drums-abnf-03.txt.

[30]       R. Turner, "Printer MIB", draft-ietf-printmib-mib-info-
     02.txt, July 12, 1997. draft-ietf-drums-abnf-04.txt.

[char]    N. Freed, J. Postel:  IANA CharSet Registration Procedures,
     Work in Progress (draft-freed-charset-reg-02.txt).

[dpa]     ISO/IEC 10175 Document Printing Application (DPA), June 1996.

[iana]    IANA Registry of Coded Character Sets:  ftp://ftp.isi.edu/in-
     notes/iana/assignments/character-sets

[ipp-r]   Wright, F. D., "Requirements for an Internet Printing
     Protocol:"

[ipp-m]   Isaacson, S, deBry, R, Hasting, T, Herriot, R, Powell, P,
     "Internet Printing Protocol/1.0: Model and Semantics"

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

7.        Author's Address

Robert Herriot (editor)             Paul Moore
Sun Microsystems Inc.               Microsoft
901 San Antonio.Road, MPK-17        One Microsoft Way
Palo Alto, CA 94303                 Redmond, WA 98053

Phone: 650-786-8995                 Phone: 425-936-0908
Fax:  650-786-7077                  Fax: 425-93MS-FAX
Email: robert.herriot@eng.sun.com   Email: paulmo@microsoft.com

Sylvan Butler                       Randy Turner
Hewlett-Packard                     Sharp Laboratories
11311 Chinden Blvd.                 5750 NW Pacific Rim Blvd
Boise, ID 83714                     Camas, WA 98607

Phone: 208-396-6000                 Phone: 360-817-8456
Fax:  208-396-3457                  Fax: : 360-817-8436
Email: sbutler@boi.hp.com           Email: rturner@sharplabs.com

IPP Mailing List:  ipp@pwg.org
IPP Mailing List Subscription:  ipp-request@pwg.org
IPP Web Page:  http://www.pwg.org/ipp/

Moore and Turner         Expires April 23, 1998

8. Other Participants:

Chuck Adams - Tektronix             Harry Lewis - IBM
Ron Bergman - Data Products         Tony Liao - Vivid Image
Keith Carter - IBM                  David Manchala - Xerox
Angelo Caruso - Xerox               Carl-Uno Manros - Xerox
Jeff Copeland - QMS                 Jay Martin - Underscore
Roger Debry - IBM                   Larry Masinter - Xerox
Lee Farrell - Canon                 Bob Pentecost - Hewlett-Packard
Sue Gleeson - Digital               Patrick Powell - SDSU
Charles Gordon - Osicom             Jeff Rackowitz - Intermec
Brian Grimshaw - Apple              Xavier Riley - Xerox
Jerry Hadsell - IBM                 Gary Roberts - Ricoh

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Richard Hart - Digital              Stuart Rowley - Kyocera
Tom Hastings - Xerox                Richard Schneider - Epson
Stephen Holmstead                   Shigern Ueda - Canon
Zhi-Hong Huang - Zenographics       Bob Von Andel - Allegro Software
Scott Isaacson - Novell             William Wagner - Digital Products
Rich Lomicka - Digital              Jasper Wong - Xionics
David Kellerman - Northlake         Don Wright - Lexmark
Software
Robert Kline - TrueSpectra          Rick Yardumian - Xerox
Dave Kuntz - Hewlett-Packard        Lloyd Young - Lexmark
Takami Kurono - Brother             Peter Zehler - Xerox
Rich Landau - Digital               Frank Zhao - Panasonic
Greg LeClair - Epson                Steve Zilles - Adobe

9. Appendix A: Protocol Examples

9.1 Print-Job Request

The following is an example of a Print-Job request with job-name,
copies, and sides specified. sides specified.

Octets                Symbolic Value       Protocol field

0x0100                1.0                  version
0x0002                PrintJob             operation
0x01                  start operation-     operation-attributes tag
                      attributes
0x47                  charset type         value-tag
0x0012                                     name-length
attributes-charset    attributes-charset   name
0x0008                                     value-length
US-ASCII              US-ASCII             value
0x48                  natural-language     value-tag
                      type
0x001B                                     name-length
attributes-natural-   attributes-natural-  name
language              language
0x0005                                     value-length
en-US                 en-US                value

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Octets                Symbolic Value       Protocol field

0x0100                1.0                  version
0x0002                PrintJob             operation
0x02                  start attributes     attribute tag

0x42                  name type            value-tag
0x0008                                     name-length
job-name              job-name             name
0x0006                                     value-length
foobar                foobar               value
0x02                  start job-           job-attributes tag
                      attributes
0x21                  integer type         value-tag
0x0005                                     name-length
copies                copies               name
0x0004                                     value-length
0x00000014            20                   value
0x44                  keyword type         value-tag
0x0005                                     name-length
sides                 sides                name
0x0001
0x0013                                     value-length
two-sided-long-edge   two-sided-long-edge  value
0x03                  start-data           data-tag
%!PS...               <PostScript>         data

9.2 Print-Job Response (successful)

Here is an example of a Print-Job response which is successful:

Octets           Symbolic Value   Protocol field

0x0100           1.0              version

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Octets           Symbolic Value   Protocol field
0x0000           OK (successful)  status-code
0x01             start parameters parameter operation- operation-attributes tag
                 attributes
0x47             charset type     value-tag
0x0012                            name-length
attributes-      attributes-      name
charset          charset
0x0008                            value-length
US-ASCII         US-ASCII         value
0x48             natural-language value-tag
                 type
0x001B                            name-length
attributes-      attributes-      name
natural-         natural-language
language
0x0005                            value-length
en-US            en-US            value
0x41             text type        value-tag
0x000E                            name-length
status-message   status-message   name
0x0002                            value-length
OK               OK               value
0x02             start job-       job-attributes tag

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Octets           Symbolic Value   Protocol field

                 attributes
0x21             integer          value-tag
0x0007                            name-length
job-id           job-id           name
0x0004                            value-length
147              147              value
0x45             uri type         value-tag
0x0008                            name-length
job-uri          job-uri          name
0x000E                            value-length
http://foo/123   http://foo/123   value
0x02             start attributes attribute tag
0x25             name type        value-tag
0x0008                            name-length
job-state        job-state        name
0x0001                            value-length
0x03             pending          value
0x03             start-data       data-tag

9.3 Print-Job Response (failure)

Here is an example of a Print-Job response which fails because the
printer does not support sides and because the value 20 for copies is
not supported:

Octets           Symbolic Value           Protocol field

0x0100           1.0                      version
0x0400           client-error-bad-request status-code
0x01             start parameters          parameter operation-         operation-attribute tag
                 attribures
0x47             charset type             value-tag
0x0012                                    name-length
attributes-      attributes-charset       name
charset
0x0008                                    value-length
US-ASCII         US-ASCII                 value
0x48             natural-language type    value-tag
0x001B                                    name-length
attributes-      attributes-natural-      name
natural-         language
language
0x0005                                    value-length
en-US            en-US                    value
0x41             text type                value-tag
0x000E                                    name-length
status-message   status-message           name
0x000D                                    value-length
bad-request      bad-request              value
0x02
0x04             start unsupported-job-   unsupported-job-
                 attributes               attributes          attribute tag

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Octets           Symbolic Value           Protocol field

0x21             integer type             value-tag
0x0005                                    name-length
copies           copies                   name
0x0004                                    value-length
0x00000014       20                       value
0x10             unsupported  (type)      value-tag
0x0005                                    name-length
sides            sides                    name
0x0000                                    value-length
0x03             start-data               data-tag

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9.4 Print-URI Request

The following is an example of Print-URI request with copies and job-
name parameters.

Octets              Symbolic Value      Protocol field
0x0100              1.0                 version
0x0003              Print-URI           operation
0x01                start-parameters    parameter                start operation-    operation-attributes tag
                    attributes
0x47                charset type        value-tag
0x0012                                  name-length
attributes-charset  attributes-charset  name
0x0008                                  value-length
US-ASCII            US-ASCII            value
0x48                natural-language    value-tag
                    type
0x001B                                  name-length
attributes-natural- attributes-         name
language            natural-language
0x0005                                  value-length
en-US               en-US               value
0x45                uri type            value-tag
0x000A                                  name-length
document-uri        document-uri        name
0x11                                    value-length
ftp://foo.com/foo   ftp://foo.com/foo   value
0x02                start-attributes    attribute tag
0x42                name type           value-tag
0x0008                                  name-length
job-name            job-name            name
0x0006                                  value-length
foobar              foobar              value
0x02                start job-          job-attributes tag
                    attributes
0x21                integer type        value-tag
0x0005                                  name-length
copies              copies              name
0x0004                                  value-length
0x00000001          1                   value
0x03                start-data          data-tag

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Octets              Symbolic Value      Protocol field
%!PS...             <PostScript>        data

9.5 Create-Job Request

The following is an example of Create-Job request with no parameters and
no attributes

Octets       Symbolic    Protocol field
             Value
0x0100       1.0         version
0x0005       Create-Job  operation
0x03         start-data  data-tag

9.6 Get-Jobs Request

The following is an example of Get-Jobs request with parameters but no
attributes.

Octets                Symbolic Value       Protocol field
0x0100                1.0                  version
0x000A                Get-Jobs             operation
0x01                  start-parameters     parameter-tag                  start operation-     operation-attributes-
                      attributes           tag
0x47                  charset type         value-tag
0x0012                                     name-length
attributes-charset    attributes-charset   name
0x0008                                     value-length
US-ASCII              US-ASCII             value
0x48                  natural-language     value-tag
                      type
0x001B                                     name-length
attributes-natural-   attributes-natural-  name
language              language
0x0005                                     value-length
en-US                 en-US                value
0x21                  integer type         value-tag
0x0005                                     name-length
limit                 limit                name
0x0004                                     value-length
0x00000032            50                   value
0x44                  keyword type         value-tag

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Octets                Symbolic Value       Protocol field
0x0014                                     name-length
requested-attributes  requested-attributes name
0x0007
0x0006                                     value-length
job-uri               job-uri
job-id                job-id               value
0x44                  keyword type         value-tag
0x0000                additional value     name-length
0x0008                                     value-length
job-name              job-name             value
0x03                  start-data           data-tag

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9.7 Get-Jobs Response

The following is an of Get-Jobs response from previous request with 3
jobs. The Printer returns no information about the second job.

Octets            Symbolic Value        Protocol field
0x0100            1.0                   version
0x0000            OK (successful)       status-code
0x01              start-parameters      parameter-tag              start operation-      operation-attribute-tag
                  attributes
0x47              charset type          value-tag
0x0012                                  name-length
attributes-       attributes-charset    name
charset
0x0008                                  value-length
ISO-8859-1        ISO-8859-1            value
0x48              natural-language      value-tag
                  type
0x001B                                  name-length
attributes-       attributes-natural-   name
natural-language  language
0x0005                                  value-length
en-US             en-US                 value
0x41              text type             value-tag
0x000E                                  name-length
status-message    status-message        name
0x0002                                  value-length
OK                OK                    value
0x02              start-attributes      attribute-tag              start job-attributes  job-attributes-tag
                  (1st  object)
0x45              uri
0x48              natural-language      value-tag
                  type
0x001B                                  name-length
attributes-       attributes-natural-   name
natural-language  language
0x0005                                  value-length
fr-CA             fr-CA                 value
0x21              integer type          value-tag
0x0007
0x0006                                  name-length
job-uri           job-uri
job-id            job-id                name
0x000E
0x0004                                  value-length
http://foo/123    http://foo/123
147               147                   value
0x42              name type             value-tag
0x0008                                  name-length
job-name          job-name              name
0x0003                                  name-length
foo               foo
fou               fou                   name
0x02              start-attributes      attribute-tag              start job-attributes  job-attributes-tag
                  (2nd object)
0x02              start-attributes      attribute-tag              start job-attributes  job-attributes-tag
                  (3rd object)
0x45              uri
0x21              interger type         value-tag
0x0007
0x0006                                  name-length
job-id            job-id                name

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Octets            Symbolic Value        Protocol field
0x0004                                  value-length
148               148                   value
0x13              compoundValue         value-tag
0x0008                                  name-length
job-name          job-name              name
0x0004                                  value-length
0x0002            2                     value (number of values)
0x48              naturalLanguage       value-tag
0x0000            muli-value marker     name-length
job-uri           job-uri               name
0x000E
0x0005                                  value-length
http://foo/124    http://foo/124
de-CH             de-CH                 value
0x42              name type             value-tag
0x0008
0x0000            muli-value marker     name-length
job-name          job-name              name
0x0003                                  name-length
bar               bar                   name
0x03              start-data            data-tag

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10. Appendix B: Mapping of Each Operation in the Encoding

The next three tables show the results of applying the rules above to
the operations defined in the IPP model document. There is no
information in these tables that cannot be derived from the rules
presented in Section 3.8 "Mapping of Parameter Attribute  Names".

The following table shows the mapping of all IPP model document model-document request
parameters
attributes to a parameter-sequence, attribute-sequence an appropriate xxx-attribute-sequence  or special position
in the protocol.

The table below shows the attributes for operations sent to a Printer
URI.

Operation        parameter-      attribute-        operation       job attributes  special position
                 sequence        sequence

Get-Operations   printer-uri
                 attributes

Print-Job        printer-uri        attributes-     job-template    document-content
                 best-effort
                 charset         attributes
                 attributes-
                 natural-
                 language
                 job-name        document
                                 attributes
Print-URI        printer-uri
                 document-name
                 ipp-attribute-
                 fidelity
                 document-
                 charset
                 document-
                 natural-
                 language
Create-Job or    attributes-     job-template
                 best-effort
Validate-Job     charset         attributes
                 job-name        document
                 document-uri
                 attributes-
                 natural-

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Operation        operation       job attributes
Validate-Job or  printer-uri  special position
                 attributes

                 language job-
                 name
                 ipp-attribute-
                 fidelity
Print-URI        attributes-     job-template
Create-Job       best-effort
                 charset         attributes
                 job-name
                 attributes-
                 natural-
                 language job-
                 name
                 ipp-attribute-
                 fidelity
                 document-uri
                 document-
                 charset
                 document-
                 natural-
                 language
Send-Document    job-uri         document         document-content    attributes-
                 charset
                 attributes-
                 natural-
                 language job-id
                 last-document   attributes
                 document-name
                 document-
                 charset
                 document-
                 natural-                                                        document-content
                 language
Send-URI         job-uri         document         attributes-
                 charset
                 attributes-
                 natural-
                 language job-id
                 last-document   attributes
                 document-name
                 document-uri
                 document-
                 charset
                 document-
                 natural-
                 language
Cancel-Job       job-uri       attributes-
                 charset
                 attributes-
                 natural-
                 language job-id
                 message
Get-Attributes   printer-uri   attributes-

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Operation        operation       job attributes  special position
                 attributes

(for a Printer)  document-
                 format  charset
                 attributes-
                 natural-
                 language
                 requested-
                 attributes
                 document-format
Get-Attributes   job-uri   attributes-
(for a Job)      document-
                 format      charset
                 attributes-
                 natural-
                 language job-id
                 requested-
                 attributes
Get-Jobs         printer-uri         attributes-
                 charset
                 attributes-
                 natural-
                 language limit
                 requested-
                 attributes
                 which-jobs

The following table below shows the attributes for operations sent to a Job URI.

Operation        operation       job attributes  special position
                 attributes

Send-Document    attributes-                     document-content
                 charset
                 attributes-
                 natural-
                 language last-
                 document
                 document-name
                 document-
                 charset
                 document-
                 natural-
                 language
Send-URI         attributes-
                 charset
                 attributes-
                 natural-
                 language last-
                 document
                 document-name
                 document-uri
                 document-

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Operation        operation       job attributes  special position
                 attributes

                 charset
                 document-
                 natural-
                 language
Cancel-Job       attributes-
                 charset
                 attributes-
                 natural-
                 language
                 message
Get-Attributes   attributes-
(for a Job)      charset
                 attributes-
                 natural-
                 language
                 requested-
                 attributes

The following two tables shows the mapping of all IPP model document model-document
response
parameters attributes to a parameter-sequence, attribute-sequence an appropriate xxx-attribute-sequence or special
position in the protocol.

Operation      operation     job-         unsupported-job-   special
               attributes    attributes   attributes         position

Print-Job,     attributes-   job-id       unsupported        status-
Print-URI,     charset       job-uri      attributes         code
Create-Job,    attributes-    job-state
Send-Document  natural-      job-state-
or Send-URI    language      reasons
               status-       job-state-
               message       message
                             number-of-
                             intervening
                             -jobs

Validate-Job   attributes-                unsupported        status-
               charset                    attributes         code
               attributes-
               natural-
               language
               status-
               message

Note: the unsupported-job-attributes are present only if the client
included some job attributes that the Printer doesn't support.

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Note:  the job-attributes are present only if the server returns the
status code of successful-ok or successful-ok-ignored-or-substituted-
attributes.

Operation      parameter-sequence    attribute-sequence      operation     job-         printer-      special
                                                           position

Get-Operations status-message                              status-code
               supported-operations

Print-Job,     status-message        job-status            status-code
Print-URI or   job-uri
               attributes
Create-Job

Send-Document  status-message        job-status            status-code
or Send-URI    attributes

Validate-Job   status-message                              status-code   attributes    position

Cancel-Job     status-message     attributes-
               charset
               attributes-
               natural-
               language
               status-                                                               status-code
               message

Get-Attributes status-message attributes-   requested                  status-code
(of a job)     charset       attributes
               attributes-
               natural-
               language
               status-
               message

Get-Attributes attributes-                requested     status-code
(of a printer) charset                    attributes
               attributes-
               natural-
               language
               status-
               message

Get-Jobs       status-message       attributes-   requested attributes                  status-code
               charset       attributes
               attributes-   (see the
               natural-      Note below)
               language
               status-
               message

Note for Get-Jobs: there is a separate attribute-sequence job-attribute-sequence containing
requested-attributes for each job object in the response

The

11. Appendix C: Hints to implementors using IPP with SSL3

WARNING: Clients and IPP objects using intermediate secure connection
protocol solutions such as IPP in combination with Secure Socket Layer
Version 3 (SSL3), which are developed in advance of IPP and TLS
standardization, might not be interoperable with IPP and TLS standards-
conforming clients and IPP objects.

Moore and Turner         Expires April 23, 1998

An assumption is that the URI for a secure IPP Printer object has been
found by means outside the IPP printing protocol, via a directory
service, web site or other means.

IPP provides a transparent connection to SSL by calling the
corresponding URL (a https URI connects by default to port 443).
However, the following table shows functions can be provided to ease the mapping integration
of all IPP model with SSL during implementation.

connect (URI), returns a status.

  "connect" makes an https call and returns the immediate status of
  the connection as returned by SSL to the user. The status values are
  explained in section 5.4.2 of the SSL document error
response parameters [ssl].

  A session-id may also be retained to later resume a parameter-sequence, attribute-sequence or
special position in session.  The SSL
  handshake protocol may also require the protocol. Those operations omitted don't have
special parameters cipher specifications
  supported by the client, key length of the ciphers, compression
  methods, certificates, etc. These should  be sent to the server and
  hence should be available to the IPP client (although as part of
  administration features).

disconnect (session)

  to disconnect a particular session.

  The session-id available from the "connect" could be used.

resume (session)

  to reconnect using a previous session-id.

The availability of this information as administration features are left
for an error return.

Operation        parameter-      attribute-sequence       special
                 sequence                                 position

Print-Job,       status-message  unsupported attributes   status-code
Print-URI,
Validate-Job,
Create-Job,
Send-Document or
Send-URI implementors, and need not be standardized at this time

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