IPP Mail Archive: RE: IPP> Document object spec Conformance

RE: IPP> Document object spec Conformance ISSUES and proposals fo r Operations

From: Zehler, Peter (PZehler@crt.xerox.com)
Date: Thu May 15 2003 - 07:42:48 EDT

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    Tom,
    I agree. My only comment is in item 1 below.
    Pete

                                    Peter Zehler
                                    XEROX
                                    Xerox Architecture Center
                                    Email: PZehler@crt.xerox.com
                                    Voice: (585) 265-8755
                                    FAX: (585) 265-8871
                                    US Mail: Peter Zehler
                                                    Xerox Corp.
                                                    800 Phillips Rd.
                                                    M/S 128-30E
                                                    Webster NY, 14580-9701

    -----Original Message-----
    From: Hastings, Tom N [mailto:hastings@cp10.es.xerox.com]
    Sent: Wednesday, May 14, 2003 6:38 PM
    To: iPP@pwg.org
    Subject: IPP> Document object spec Conformance ISSUES and proposals for
    Operati ons

    For discussion at the Thursday, May 15, SM Telecon:

    Peter and I would like to propose that a goal for the Document Object spec
    itself (the part that remains after having some of it split into two other
    specs) is:

    Simplify the Document object spec and maximize the interoperability by
    having as few OPTIONAL operations as possible.

    Thus we propose the following Operation Conformance requirements for the
    Document object spec over and above RFC 2911. We'd like to see if there is
    general agreement on the mailing list and at the telecon:

    1. Remove the Create-Document and Send-Data operations from the spec
    (asuming that we can't get agreement to make them REQUIRED). See previous
    exchange between Michael Sweet and myself about this minor advantages of
    Create-Document and Send-Data and the additional denial of service attacks
    that they provide which as the same as Create-Job and Send-Document.

    Rationale: A client MAY validate each document individually with
    Validate-Job before sending any document data of any of the documents.
    However, the added advantage of being able to validate a multi-document job
    with dissimilar documents that might not be able to be accepted as a single
    Job is not worth having these new Create-Document and Send-Data operations.
    <PZ> I agree. Let's get rid of Create-Document and Send-Data.
    I've always considered this a corner case. Any Printer can offer this
    capability through the use of multi-document jobs, ValidateJob AND page
    level Overrides. A complicated way to go when we already have Cancel-Job
    to handle the rare case where Documents contain conflicting processing
    instructions within a multi-Document Job on a Printer front ending
    multiple dissimilar Printers that is encountered.</PZ>
    Also Create-Document and Send-Data will require similar defensive
    implementation in the Printer for Denial of Service attacks as do Create-Job
    and Send-Document.

    2. Make Create-Job and Send-Document REQUIRED.

    3. Make support of multi-document Jobs REQUIRED.

    Rationale: The real advantage of the Document object is for multi-document
    jobs. Supporting the Document object only for Print-Job isn't really worth
    the implementation cost for the very little end user benefit.

    4. Keep the new Get-Documents, Get-Document-Attributes, Cancel-Document
    REQUIRED.

    5. Keep old Send-URI, and new Delete-Document, and new
    Set-Document-Attributes OPTIONAL.

    So the REQUIRED extensions from RFC 2911 are:

    a. the added Document Template attributes group to the Send-Document (and
    Send-URI, if implemented) operation where any Job Template attribute that
    applies to an individual document may be supplied.

    b. the added corresponding Document Description attributes that correspond
    to the RFC2911 Operation and Job Description attributes.

    c. The RFC2911 Create-Job, Send-Document become REQUIRED and multi-document
    jobs become REQUIRED.

    d. The new Get-Documents, Get-Document-Attributes, Cancel-Document
    operations remain REQUIRED.

    Everything else remains OPTIONAL.

    Comments?

    Thanks,
    Tom and Peter



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