Subject: [Mpls-interop] MEP to MIP processing

From: Rahul Aggarwal <[email-masked]>
Date: Thu, 17 Apr 2008 17:33:44 -0700 (PDT)

I would like some clarification on MEP to MIP processing. Slide 47
describes TTL expiration at the MIP as the mechanisms to do MEP to MIP
monitoring. That is fine.

But then slide 65 in the pseudocode talks about the MIP looking at LFU
below the top label in the stack in the swap case and taking action
accordingly. IMO this is a noticeable change to the MPLS
processing on a transit router and requires a transit router to look at
the label below the top label for every packet.

The question is why is the procedure on slide 65 needed given that there
is a mechanism to do this based on TTL expiration as on slide 47 (and then 59
and 60) ? Can we delete the procedure on slide 65 ?

rahul

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From: David Ward <[email-masked]>
Date: Thu, 17 Apr 2008 20:52:56 -0500

Not every packet has to be examined, just the ones w/ TTL expired.  
FWIW, this was discussed on the list about a month ago and considered  
acceptable for selecting option 1. Note that the slides do not  
represent the entirety of the chosen design. It is the output of a  
feasibility analysis that a solution can be found.

-DWard

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From: David Ward <[email-masked]>
Date: Thu, 17 Apr 2008 20:55:58 -0500

Ah but, I see that it isn't what slide 65 says  in the case of swap,  
my error. I believe that the SWAP operation can and should be deleted  
given the other procedures you cite.

-DWard

On Apr 17, 2008, at 8:52 PM, David Ward wrote:

> FWIW, this was discussed on the list about a month ago and  
> considered acceptable for selecting option 1. Note that the slides  
> do not represent the entirety of the chosen design. It is the  
> output of a feasibility analysis that a solution can be found.
>
>
>
> -DWard
>

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From: Rahul Aggarwal <[email-masked]>
Date: Fri, 18 Apr 2008 07:59:16 -0700 (PDT)

Hi David,

> given the other procedures you cite.

Great. We are in agreement.

rahul