Subject: RE: An observation

From: "Schliesser, Benson" <[email-masked]>
Date: Fri, 11 Nov 2005 14:12:59 -0600

Mark-
 
> - InterAS: We have documented 10a, 10b, and 10c, it seems to be well
> understood, but perhaps we want a 10d as well.

My perspective as a provider is that a, b, and c are a poor set of
options to choose from. I find each option to be some combination of
difficult-to-manage and over-exposing. However the "option d" described
by draft-kulmala-l3vpn-interas-option-d appears to be a good model that
I would like to see progress on.

> - Multicast: We have a documented solution, but perhaps we want to do
> something different with BGP or PWs instead.

I am in process of reading through the new drafts (which is more painful
than it ought to be), so I can't comment very specifically yet. But in
general, I can say a couple things.

The previously documented solution is incomplete and/or sub-optimal. I
would like to see a better solution and I believe the presence of this
discussion in the WG is evidence that I am not alone in this thinking. I
believe it would benefit everybody if we continued progress in this
topic.

However I find the new proposals suffering in several ways, especially
from complexity, and it is possible that not all of them can count as
"progress". I applaud and encourage more work on the
underlying/fundamental issues, problem analysis, requirements, etc. More
of this should be done before we try to shoe-horn new solutions--perhaps
a bit of perspective would be valuable to the authors of these new
drafts.

> - IPv6: We have documented IPv6 L3VPNs, but perhaps we want to
translate
> addresses at the edge rather than encapsulate in tunnels.

I have to agree with your questioning of this topic. I tend to believe
that the mechanisms of a L3 VPN should apply equally (generically even?)
to IPv4 and IPv6 and perhaps other L3 protocols, and I think our current
model is a good foundation for this. Of course, it might be nice if we
had some open discussion about the applicability of L3VPN to IPv6 in the
first place. (i.e., Do the motivators for a VPN in IPv4 still exist in
IPv6? If so what are they?)

> Are we solving significant problems, or making work for ourselves?
>
> Comments appreciated.

I appreciate your questions; thank you for posting them to the list. I
hope others will chime in with their comments, contradictions, etc.

Cheers,
-Benson

---

From: Marshall Eubanks <[email-masked]>
Date: Sat, 12 Nov 2005 09:46:55 -0500

Hello;

> a bit of perspective would be valuable to the authors of these new

As Nidhi Bhaskar said after the PIM WG  meeting, multicast is
complicated, L3VPN is complicated, Multicast-L3VPN's are going to be
very complicated.

I think, with the cross-fertilization at the recent IETF, that the
multicast community has woken up to the challenge of L3VPNs, and I
hope that there may be some rapid progress in this area. I think that
changes are needed in PIM to support this, and I believe that there is
now buy-in from the PIM-WG for doing these changes in a rapid manner
(i.e., via L3VPN extensions to PIMv2, instead of creating PIMv.3).

I do not want there to be a fork in multicast development, with two
separate communities of developers. I do not see that this is in
anyone's benefit.

Regards
Marshall Eubanks