Subject: LSR MIB mplsInSegmentMapTable

From: "Adrian Farrel" <[email-masked]>
Date: Sat, 5 Jul 2003 16:13:23 +0100

Hi,

I'm going through the latest LSR MIB updating the Management Overview.  I
notice that mplsInSegmentMapTable is indexed by a RowPointer.  Do you
really, really want to do this?

Also, the description says...

      "This table specifies the mapping from the
        mplsInSegmentIndex to the corresponding
        mplsInSegmentInterface and mplsInSegmentLabel
        objects. The purpose of this table is to..."

But the indexing is the other way around. That is, it provides a mapping
from interface and label to in-segment.

Cheers,
Adrian

---

From: "Thomas D. Nadeau" <[email-masked]>
Date: Sun, 6 Jul 2003 09:37:11 -0400

> Hi,
> 
> I'm going through the latest LSR MIB updating the Management 
> Overview.  I notice that mplsInSegmentMapTable is indexed by 
> a RowPointer.  Do you really, really want to do this?

	This is what was requested during the last call
to support LSP tracing. That is a mapping from
the interface + label or interface + label pointer 
to the inSegmentIndex. The table achieves this by being 
indexed by:

           { mplsInSegmentMapInterface, 
             mplsInSegmentMapLabel,
             mplsInSegmentMapLabelPtrIndex }

	and returning mplsInSegmentMapIndex as the
single object in each row.  The reason why a 
RowPointer is needed is to support the cases
where a short MPLS label is mapped, as well as
an extended (i.e.: GMPLS) label. Use of a RowPointer
in the normal case will result in that index
being simply set to 0.0, otherwise it will 
indicate where to find the label (and the middle
index should be set to 0). In both cases, the
mapping back to the mplsInSegmentIndex is achieved.

> But the indexing is the other way around. That is, it 
> provides a mapping from interface and label to in-segment.

	I suppose that you can interpret the text
that way. Maybe I am dyslexic, but I interpreted it 
correctly. 8)

	--Tom