Re: Dense?

[Bob Stewart <[e-mail]>]

This seems to be Dave's week for good questions and mine for opinions.

>If an agent (in either the terminal server or the
>router) implements the chassis MIB, if
>the entries in the slot table are numbered
>1 to 8 so that they correspond to the physical
>slots is this dense or sparse?

Aha!  I see the problem.  I think of sparse or dense referring to holes in the
numbering when I do a get or get-next.  If get-next returns 1-2-3-4-5-6-7-8,
that's dense, if it returns 4-6-8, that's sparse, that is, it didn't return
the empty slots. 

>If the entries
>in the slot table were numbered 2 (slot 1), 4 (slot 2),
>8 (slot 3), 16 (slot 4), 32 (slot 5), 64 (slot 6),
>128 (slot 7), and 256 (slot 8), then I would say these
>would be "sparse".

The widely spaced funny numbering is also allowable and
would most likely be handled as sparse as the between numbers don't even
correspond to anything.

>However, I don't understand what
>situations that this numbering would be appropriate?

Hmmmm.  If the "chassis" were really big, you might number by cabinet * 256 +
shelf * 16 + slot.  That would have lots of abstract slots.  That's perhaps a
bit weird, but we're not tying "chassis" strictly to a single, relatively
small card cage.

>And again, would it be Ok for the router that implemented
>the chassis MIB to use the first numbering, and the
>terminal server that also implemented the chassis
>MIB to use the second numbering?

I'd say no.  I believe they should be the same.

>Also note that the power supply is a "dumb"
>"logical device" that doesn't have an agent
>and doesn't have a MIB (yet).  How does it
>fit into the chassis MIB model?

Going out on a bit of a limb, it should show up as an entry like any other
device and I guess the chassis agent would have to pull its information out of
thin air.

>Finally, is this simple example a "good" one to
>use for further discussion?  What other additional
>information needs to be added (maybe information
>about backplane(s))?

Sounds pretty good to me.  It should probably have a couple of segments to
play with.  If you'd like to try provoking some discussion, let it have a
repeater card and let that repeater card be able to hook to two different
segments at the same time and not repeat them.

	Bob