Subject: Question on Draft IETF MPLS LSR MIB 07: Segment and XC tables indexes

From: "Dave Danenberg" <[email-masked]>
Date: Mon, 12 Feb 2001 08:59:19 -0500

I just noticed that Section 8 "Example of LSP Setup" and the MIB objects
conflict. The example shows the XCTable referencing entries in the
segmentTables, but the segment entries do not reference the XC table
entry. then looking at the actual MIB you see the opposite: the in and
out segment entries each reference the XC entry, but the XC entry does
not reference the segments.
 
I would think it would be useful for the XC entry to reference the
segments as shown in the example. Starting from a tunnel entry, you can
get to the XC entry, but then you can not get to the cross-connect
segments. I would think that you would especially need the inSegment
indexes for obtaining the inbound label. 
 
Is this something, that has been noted already? Will the Example vs MIB
conflict be resolved? Will the segment indexes be added to the XC table?
 
Thanx,
Dave

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From: "Thomas D. Nadeau" <[email-masked]>
Date: Mon, 12 Feb 2001 09:55:08 -0500

>conflict be resolved?

         In the example, the XC references (through its indexes)
outSegment=1 and ifIndex=12,inSegment=21. There is no problem
here as you can get back to the segments from the XCtable by
simply looking at the indexes that you have for the object
you are looking at in the XC table. From the InSegment table
you can find all of the XCs which apply by looking at the
XC indexes containing: (*,ifIndex,inSegmentIndex,*). From the
other side you can do: (*,*,*,outSegmentIndex).

>Will the segment indexes be added to the XC table?

         No; they are part of the indexes already.

         --Tom