Re: [Agentx] Questions on requirements

["Randy Presuhn" <randy_presuhn at mindspring.com>]

Hi -

> From: "Magnus Fromreide" <magfr at lysator.liu.se>
> To: <agentx at ietf.org>
> Sent: Sunday, October 14, 2007 11:48 PM
> Subject: [Agentx] Questions on requirements
>
> In 7.2.3 it is stated that a conforming subagent MUST support -Get,
> -GetNext and -GetBulk.
> 
> In 7.2.4 it is stated that a conforming subagent MUST support -TestSet,
> -CommitSet, -UndoSet and -CleanupSet.
> 
> I think thoose requirements are excessive.
> 
> Consider a subagent that only implements read-only variables.
> In that case there should be no need to implement neither of -CommitSet,
> nor -UndoSet since the -TestSet response will make sure that there will
> be no -CommitSet and thus no -UndoSet for the transaction.
> 
> Consider a subagent that implements no variables.
> In that case there should be no need for neither of -Get, -GetNext,
> -GetBulk, -TestSet, -CommitSet, -UndoSet nor -CleanupSet since the
> absence of any -RegisterPDUs should make certain that no requests for
> variables are sent to the subagent.
...

I disagree with this reasoning both theoretical and practical grounds.
A robust implementation of any protocol cannot assume that its
communication partners will be well-behaved.  On the practical side,
as an implementor, it is *much* simpler to *not* have differing
conformance requirements.  It's much simpler to do the Agentx protocol
once, for all configurations, rather than hacking out multiple
implementations to fit various subsets.

Randy