3. Requirements

3.1. Rationale for IPP/2.0

The Printer MIB v2 [RFC3805] and Port Monitor MIB [PWG5107.1] define:

    (a) Model of Print Devices

    (b) Operations for Print Devices
        - prtGeneralReset
        - prtConsoleDisable

    (c) Groups of simple attributes for Print Devices
        - prtInputTable --> prtInputName
        - ppmPortTable --> ppmPortServiceNameOrURI

    (d) Conformance requirements for implementations of Printer MIB v2
        and Port Monitor MIB


The IPP/1.1 Model and Semantics [RFC2911] defines:

    (a) Model of Print Services, Print Devices, and Print Jobs

    (b) Operations for Print Services and Print Jobs
        - Pause-Printer
        - Print-Job

    (c) Attributes for Print Services and Print Jobs
        - printer-location
        - job-id

    (d) Conformance requirements for implementations of IPP/1.1


The IPP/1.1 Encoding and Transport [RFC2910] defines:

    (a) Protocol Bindings for IPP/1.1
        - HTTP with optional upgrade to TLS

    (b) Mappings of operations for Print Services and Print Jobs
        Jobs.

    (c) Conformance requirements for implementations of IPP/1.1


Later IETF and PWG standards-track specifications defined 14 IPP/1.1
extensions including:

    (a) New operations
        - Set-Printer-Attributes [RFC3380]
        - Resume-Job [RFC3998]

    (b) New attribute syntaxes
        - collection [RFC3382]

    (c) New objects
        - Subscription [RFC3995]
        - Document [PWG5100.5]


Current enterprise printers often support functionality standardized in
these IPP/1.1 extensions (in a proprietary manner).  In order to support
user requirements for advanced printing functionality, there is a clear
need to standardize profiles of these IPP/1.1 extensions for reliable
interoperability and to encourage adoption of IPP-based infrastructure.


3.2. Use Models

See the definitions of Workgroup Printer, Enterprise Printer, and
Production Printer in section 2 Terminology above.


3.2.1. Workgroup Printer

Alice, Bob, and Charlie are graphic artists who share a workgroup
printer down the hall.  They all load paper when needed.  Alice and Bob
have convinced Charlie that he should load the toner cartridges.  But
they do use many paper sizes - they need PWG Media Standardized Names
[PWG5101.1] used in the IPP 'media' attribute.  And they print lots of
thumbnails of graphic images - they need standard IPP document formats.


3.2.2. Enterprise Printer

Joe and his colleagues send large documents to an enterprise printer in
a building across the street in a 'glasshouse' with some web servers.
Both Joe and the operator Sue in the glasshouse manage lots of jobs -
they need to hold and release jobs.  Joe wants to keep track of his jobs
- he needs to subscribe for job events.  Sue is expected to manage
several printers - she needs to enable and disable printers (i.e.,
enable/disable accepting new jobs over input channels).


3.2.3. Production Printer

Louise works in Accounting for a big wholesaler in Kansas City.  She
sends variable data jobs (e.g., different user names, user addresses,
and balance owed amounts formatted onto a pre-printed form) to a
production printer in Chicago.  Her friend Sam is a night-shift operator
in Chicago.  Sam has to make sure that job resources (e.g., the
pre-printed forms for Louise's jobs) are loaded when needed - he often
needs to pause the printer after the current job.