Re: making a display hint RECOMMENDED in non-enum TCs

[Juergen Schoenwaelder <j.schoenwaelder@iu-bremen.de>]

On Tue, Jul 22, 2003 at 12:34:59PM -0700, C. M. Heard wrote:
> 
> The new section might then look something like this:
> 
> 4.6.3 DISPLAY-HINT Clause
> 
>    The DISPLAY-HINT clause is used in a TC to provide a non-binding hint
>    to a management application as to how the value of an instance of an
>    object defined with the syntax in the TC might be displayed.  Its
>    presence is optional.
> 
>    Although management applications typically default to decimal format
>    ("d") for integer TCs and to ?????? format ("??") for octet string
>    TCs when the DISPLAY-HINT clause is absent, it should be noted that
>    SMIv2 does not actually specify any defaults.  MIB authors should be
>    aware that a clear hint is provided to applications only when the
>    DISPLAY-HINT clause is present.

I like the proposal. Some changes to the second paragraph:

     Although management applications typically default to decimal format
     ("d") for integer TCs which are not enumerations and to a hexadecimal
     format ("1x:" or "1x " or "1x_") for octet string TCs when the 
     DISPLAY-HINT clause is absent, it should be noted that SMIv2 does 
     not actually specify any defaults.  MIB authors should be aware that 
     a clear hint is provided to applications only when the DISPLAY-HINT 
     clause is present.

I am not sure the hexadecimal formats for OCTET STRING values are all
the same. The scotty package uses "1x:" while NET-SNMP seems to use
"1x " and tcpdump uses "1x_", but I am sure there are other packages 
which use other formats. I just learned that ethereal uses "1d." (but
perhaps this can be fixed once this ID becomes and RFC ;-).

/js

-- 
Juergen Schoenwaelder		    International University Bremen
<http://www.eecs.iu-bremen.de/>	    P.O. Box 750 561, 28725 Bremen, Germany