IPP> MOD - document-format-supported using MIME types and 'a

IPP> MOD - document-format-supported using MIME types and 'a

IPP> MOD - document-format-supported using MIME types and 'a

Roger K Debry rdebry at us.ibm.com
Thu Aug 21 10:02:38 EDT 1997


The only thing that worries me a bit is the complexity of this when
the IPP Printer is on a server that is driving multiple physical printers.
If the physical printers have different capabilities in this regard (maybe
one senses languages A and B, another senses B and C, one has
not autosensing capability at all, and the last I can't tell. What does the
server report in this case?


Roger K deBry
Senior Technical Staff Member
Architecture and Technology
IBM Printing Systems
email: rdebry at us.ibm.com
phone: 1-303-924-4080




---------------------- Forwarded by Roger K Debry/Boulder/IBM on 08/21/97 07:53
AM ---------------------------


        ipp-owner @ pwg.org
        08/20/97 04:25 PM
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Subject: IPP> MOD - document-format-supported using MIME types and 'a


We had an IPP telecon today and discussed the issue of changing IPP from
using Printer MIB enums for document-format to using MIME-types.


Attending:  Steve Zilles, Ira McDonald, Lee Farrell, Roger deBry, Tom Hastings


I took the action item to write up the discussion on this point.


A problem that Don brought up in the e-mail was that we would have
trouble registering a MIME-type for the Printer MIB langAutomatic enum:


langAutomatic(37),
                                   -- Automatic PDL sensing.  Automatic
                                   -- sensing of the interpreter
                                   -- language family by the printer
                                   -- examining the document content.
                                   -- Which actual interpreter language
                                   -- families are sensed depends on
                                   -- the printer implementation.




The solution that we came up with today for IPP is to add a
Printer attribute called: "document-formats-detected" (or
"document-formats-auto-sensed"?).  This new IPP attribute solves two problems:


1. it would eliminate the need to register an equivalent langAutomatic
MIME type which would probably be refused


2. we make it clear to the client which of the document-formats-supported
can be auto-sensed.  Some implementations support more document-formats
than can be automatically sensed.  For example, some implementation support
PostScript, PJL, and some document format that cannot be reliabilbly sensed.


The "document-formats-detected" Printer attribute would be multi-valued
that parallels the "document-formats-supporter Printer attribute and
has a value for each of the values of the "document-formats-supported"
Printer attribute.  Each value would be a keyword that indicates whether the
corresponding document format is auto-sensed or not.  Perhaps, we can even
have more than two keyword values depending on the degree or reliability
that the PDL can be sensed.  The keyword values might be:


   'auto-detected'
   'auto-detectedd-best-effort'
   'not-auto-detected'


or using the Printer MIB terminology of 'sense', insted of 'detect':


   'auto-sensed'
   'auto-sensed-best-effort'
   'not-auto-sensed'


Alternatively, the same values could indicate whether the
client needs to supply the "document-format" attribute when submitting
each document or not, so that the following keyword values might be better
names for the corresponding semantics:


   'document-format-not-required'
   'document-format-recommended'
   'document-format-required'




Job Monitoring MIB
------------------


The Job Monitoring MIB has both representations for document format, so
we'll certainly leave the Job Monitoring MIB with both Printer enum
and MIME-type.






Printer MIB
-----------


We also discussed the suggestion from Munich that the Printer MIB
should add a new object to contain the MIME-type that corresponds to the
interpreter language.  There was support for having BOTH the current
enum and the MIME-type and the both are useful.  For example, the Printer
MIB still needs to indicate langAutomatic(37), since we would not be
adding the equivalent of the IPP "document-formats-detected" to the MIB.
For interpreter table entries that indicate langAutomatic(37), the
corresponding MIME-type name would be a zero-length string.


So we would reject the suggestion to make the prtInterpreterLangFamily object
obsolete.  We even can give the above reason not to deprecate it.




Comments?


Tom



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