IPP> MOD: Proposal to improve job submission in IPP 1.0

IPP> MOD: Proposal to improve job submission in IPP 1.0

Keith_Carter at aussmtp.austin.ibm.com Keith_Carter at aussmtp.austin.ibm.com
Fri May 2 14:27:24 EDT 1997


  Roger deBry and I want to propose a change to the IPP Model that
  delineates job and document boundaries through IPP operations rather than
  relying on an underlying protocol to do so.  In our opinion, recent email
  has indicated that chunking and multi-part MIME will complicate IPP
  implementations. We believe using IPP operations will simplify IPP
  implementations. We would like to discuss this proposal at the IPP Model
  call on Friday, May 2.


  Rather than write alot of words at this point, here is an example of
  submitting a job with 3 documents.  The first document, DOC1, uses
  multiple writes to send to the Printer.  The second document, DOC2, is a
  reference to a URL. The third document, DOC3, can be sent in single
  write.


  CreateJob (Printer URL, job-template attributes and values)
    SendDocument (Job URL, document-name=DOC1, document-part=first,
                  data-length=500, <data>)
    SendDocument (Job URL, document-name=DOC1, document-part=middle,
                  data-length=500, <data>)
    SendDocument (Job URL, document-name=DOC1, document-part=middle,
                  data-length=500, <data>)
    SendDocument (Job URL, document-name=DOC1, document-part=last,
                  data-length=150, <data>)
    SendDocument (Job URL, document-name=DOC2, document-URL=<url>)
    SendDocument (Job URL, document-name=DOC3, document-part=only,
                  data-length=100, <data>)
  EndJob (Job URL)


  CreateJob is the operation suggested in proposals from Randy Turner and
  Bob Herriot.  SendDocument and EndJob are new operations.


  For SendDocument, the  document-part attribute allows an IPP Client to
  specify the part of the document data that is being sent as follows:


  first = first set of data sent for a document
  middle = set 2 to n-1 of data sent for a document
  last = last set (n) of data sent for a document
  only = only set of data sent for a document


  document-part=first must be paired with document-part=end.
  document-part=middle is optional but can only be sent after
  document-part=first and before document-part=last.  document-part=only
  can be sent once per document object.  document-part=only cannot be sent
  between document-part=first and document-part=last.


  The benefits of this proposal are as follows:


  1.  An IPP Server can easily distinguish document boundaries based
      on a standard Model operation.
  2.  An IPP Server can easily distinguish end-of-job based on a standard
      Model operation.
  3.  An IPP Server has the opportunity to respond with status at several
      points throughout the transmission of a job (i.e. provide status
      in the response to SendDocument and EndJob).
  4.  The IPP Operations map more easily to APIs that IPP Applications
      might use to submit IPP requests.


  If the IPP working group agrees with this proposal, then Roger and/or I
  will write a more thorough description for the IPP Model spec which the
  IPP working group can subsequently review.


  Enjoy,


  Keith



More information about the Ipp mailing list