Subject: aMACControlFunctionsSupported

From: John Flick <[email-masked]>
Date: Thu, 5 Nov 1998 17:24:42 -0800 (PST)

Previously, I wrote:

> > Issue 2:
> >     - dot3ControlFunctionsSupported: Is it needed, or is it redundant
> >       with ifMauAutoNegCapability?  Should it be settable (as in the
> >       IEEE doc)?  If so, what does it mean to set it?
> > Chair's comment is that this is not redundant.
>
>I have some concerns about this object.  The IEEE doc specifies this
>object as read-write.  Does this mean an implementation is supposed to 
>suddenly figure out how to support a previously unsupported function
>because you set a new bit in the object?  This obviously doesn't make
>sense, which suggests that this object should be read-only.  If we
>want a read-only FunctionsSupported object and a read-write
>FunctionsEnabled object, that seems to overlap the function of
>ifMauAutoNegCapAdvertized, at least for all ControlFunctions that have 
>been defined so far.  I would suggest perhaps keeping a read-only
>Capabilities object here, and using the MAU MIB object for controlling 
>what is enabled.

After thinking about this some more, I realized that the ability to
have a settable object here for enabling pause (or other future
control functions?) is needed on links that do not autonegotiate, like 
100BASE-FX or 10BASE-FL.  This would mean we do need some sort of
read-write object here, even though it would be redundant with
ifMauAutoNegCapAdvertized on interfaces that do autonegotiate.  I
still prefer having a read-only object for
dot3ControlFunctionsSupported that indicates what the interface is
capable of.  I'm not sure how best to handle the settable object.
Some options:

    - Have a read-write dot3ControlFunctionsEnabled object, with the
      same syntax as the Supported object, which indicates what is
      enabled.  One issue here is that it doesn't allow us to
      configure symmetric vs. asymmetric pause.  Is this a problem?

    - Have a separate pause config object, with a syntax to match the
      current pause mode object.

    - others?

I need the WG's guidance here so I can finish the update to this
document.  Please post your opinions soon!

Thanks,
John