Re: [pim] WGLC: draft-ietf-pim-drlb-03

["Heidi Ou (hou)" <[e-mail]>]

>>>€ In section 6.3, in case of PIM assert, should not we override the
>>>existing Assert algorithm completely and suggest that the winner should
>>>be
>>>selected based on the currently selected GDR?
>>>
>>>[heidi] Could you please elaborate the reasons why 6.3 is insufficient
>>>in
>>>[heidi] this case?
>>>
>>><Bharat>: What I was trying to ask is that is there really a need to
>>>suggest modifications in assert mechanism. Instead, let the assert
>>>mechanism use the existing algorithm as it is. The only thing we need is
>>>that we would want to reduce the traffic loss which can be avoided by
>>>making R1 and R2 not stopping the forwarding.
>>
>>
>>But we are trying to forward traffic via GDR, and that can't be done by
>>current Assert algorithm.
>>
>><Bharat>: But why you want to dictate that? Won't it be easier to left it
>>to Assert?
>>
>
>
>Are you suggesting all routers should select GDR as Assert winner?
>
>We can only enforce new rule on routers supporting the draft. For those
>don't
>Understand GDR, the Assert computation have to be done with existing
>algorithm.
>
><Bharat>: I just re-read this section. Couple of things:
>
>* A small typo in "Using the above example, assume R1 and R3 agree on the
>new GDR, which  is R3", I think it should be 'assume R1 and R2 agree"
>here.


We are talking about electing a GDR between R1 and R3, for G1. To make it
clear, I will add "for G1" there,
"Using the above example, for G1, assume R1 and R3 agree on the new GDR,
which is R3." 



>
>* I was trying to avoid changing assert metric. Can we do this? Make R1
>and R2 delete their forwarding state (or leave the local channels) when
>they see traffic being received from R3 as well? Then there is no need to
>change assert messages at all.
>


R1 and R2 may not know whether the traffic is really from a GDR or not. So
they don't silently stop forwarding, instead, they are
Still forwarding, until they are sure they are assert losers.

Thanks
- Heidi