Re: [RMONMIB] smilint messages for APM-MIB

["David T. Perkins" <dperkins@dsperkins.com>]

HI,

On the issue of 128 sub-ids (and max sub-id value of 2^32-1), it was
added to improve interoperation.

At the time it was added, there were interoperation problems of agents
and management apps. Some implementations (I seem to remember the
early CMU was like this) had OID sub-id values that the max range
was 2^16. The MIT agent supported values that were upto 2^32-1.
Many SNMP API developers required pre-allocation of OID values
of a fixed size array, and needed to "know" the max number of
sub-ids for the #define used to set the size of the array.

This issue of static vs dynamic, and then if static, what is the
max size comes up all the time in designs related to computers.

The "only" consideration that was done for MIB compilers was to
cap the range at 2^32 so that "a big number" library wasn't needed
in compilers (because at the time, "unsigned long long" support
was not generally available in the current C compilers.)

-- dave's opinion --
And by the way, I'm really grossed out by the way all SNMP APIs
that I've seen process and store OIDs. They all waste huge amounts
of space. If the range for sub-id values is modified
to be "unbounded", and the number of sub-ids is modified to be
"unbounded", then things will change. Maybe it will result in
better SNMP API for OIDs, or maybe just more grossness.
-- end of opinion --

Regards,
/david t. perkins