IPP> MOD - ISSUE: # of octets of 'text'/'name' SHALL a

IPP> MOD - ISSUE: # of octets of 'text'/'name' SHALL a

Carl-Uno Manros cmanros at cp10.es.xerox.com
Mon Oct 20 21:01:22 EDT 1997


Hmmm,


Tom seems to have worked in other standardization projects than I have.
In messaging and directory standards the meaning of an upper bound limit is
that all implementations have be able to handle it if they get a text
string of that length (without truncating it). Only if the upper limit is
exceeded, it might be truncated by the receiving side, or alternatively a
protocol error might be returned.


Hence in my view the upper bound values ARE the length that the Printer
object SHALL be able to store.


My 2 cents.


Carl-Uno


At 05:18 PM 10/20/97 PDT, Tom Hastings wrote:
>Our current Model text gives upper bounds on the lengths of the 'text' and
>'name' attributes as 4095 and 255 octets, respectively.  However, we don't
>say how many of those octets a Printer object SHALL store.  We also don't
>say what happens if a client supplies a value that is longer than
>the maximum size that a Printer supports.
>
>These are two issues that will affect interoperability.
>
>I suggest that we add two sentences something like:
>
>A Printer object SHALL support at least nnn octets in requests and responses.
>If a client supplies a value that exceeds nnn, the Printer object SHALL
>truncate the value on the right after the nnn-th octet.
>
>I propose that 'nnn' be 255 for text and 127 for names.  UTF-8 takes about
>1.7 octets per character on average for Western European names.
>
>Comments?  Lets discuss at Wednesdays telecon.
>
>Thanks,
>Tom
>
>Here is the current text:
>
>
>4.1.1 'text'
>
>The 'text' attribute syntax is a sequence of one or more characters with a
>limit of 1 to 4095 octets.  The Printer object SHALL support UTF-8 [28] and
>MAY support additional charsets provided that they are registered with IANA
>[54].
>
>...
>
>
>4.1.2 'name'
>
>The 'name' attribute syntax is the same as 'text', including the MANDATORY
>support of UTF-8 and the exception natural language mechanism, except that
>the sequence of characters is limited so that its encoded form is of length
>1 to 255 octets.  This syntax type is used for user-friendly strings, such
>as a Printer name, that, for humans, are more meaningful than identifiers.  
>
>...
>
>
>
>
Carl-Uno Manros
Principal Engineer - Advanced Printing Standards - Xerox Corporation
701 S. Aviation Blvd., El Segundo, CA, M/S: ESAE-231
Phone +1-310-333 8273, Fax +1-310-333 5514
Email: manros at cp10.es.xerox.com



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