Subject: RE: Single vs many solution(s)

From: "Hamid Ould-Brahim" <[email-masked]>
Date: Tue, 27 May 2003 11:22:34 -0400

Loa,

> 
> 1. so far I've seen multiple solutions aiming to solve the same
>     problen, e.g. the vkompella vs. kkompella discussion
> 
<snip>...

> 
> So until someone proven that that e.g. the kkompella and vkompella
> addresses different problems I will try to make the wg adopt only one.

<snip>....

> 
> Any volunteer to try describe the problem space(s)?
> 

I think since vkompella vs kkompella discussions (or more precisely
kkompella discussions) we have been moving from
one issue/topic to another not related to the drafts themselves and
if I summarize the item we can list:

a) Are there strong *technical* issues with kkompella proposal?

  There was a debate, the draft is now WG document so I assume
  the chairs and ADs concluded that there are no major technical issues 
  stopping the WG to work on the proposal. So let's move on from
  that item.
  
b) Should the WG work on more than one distinct solution
   for the same problem (problem == l2vpn service)?

   Given a) and adopting other drafts the answer is yes. 
   In fact we also indirectly debated that since IPLS and VPLS provide 
   the same "service", then a potential question is 

   "Should the wg consider IPLS and VPLS
   as solving the same problem or different problems?" 

   If it is the same problem should the wg focus only on VPLS (as a 
   superset service)? or should the WG treat l2vpn services
   for IP host/routers-based CEs as different l2vpn services?
  
c) Should the solutions all progress as PS or experimental?
   
   It looks to me it is premature to debate that item at this
   point in time.

d) Do we need multiple mechanisms for the same problem?
   (e.g., Radius and BGP discovery)?

   In my view this question should be contrasted to the approach taken 
   in solving the l2vpn problem and the requirements
   addressed in the solution. There are problems that
   are services and there are those that are mechanisms.

   Since we are working on a per-solution style, it is logical that 
   protocol choices made in one solution may not be acceptable to 
   others or will not meet the requirements for other solution. In that
   respect having multiple mechanisms (using multiple protocols)
   to be used in one or more solutions is a consequence
   of both the approach taken and the reality of ppvpn problem space
   -as being 'provider-centric technology/services' instead of
   being only 'protocol-centric' problem. Therefore I don't
   see the value of addressing this item (nothing wrong 
   discussing the technical aspects though).

e) Concerns on the use of BGP (routing protocol) for implementing
   VPN functions.

   Using BGP for implementing VPN functions is a valid approach 
   and so far since l3vpns we know about the applicability of 
   BGP-based mechanisms in the field more than any other mechanism. 

   It looks to me Yakov's request to put clearly on the table
   the IESG concerns (if any) for this item is a reasonable request. 
   That will allow the WG to debate the items that are really of 
   concerns or need to be addressed and highlighted..and that will just
   improve the quality of wg outputs. 

<snip> 

> BTW - I suggest tht we start dropping copies to the ppvpn-list for
> anything that is not vpn generic.
> 

If I am not mistaken, I think the debate on l2vpn mailing list is on 
the charter only.

Hamid.

---

From: Loa Andersson <[email-masked]>
Date: Tue, 27 May 2003 19:47:03 +0200

Folks,

Haid is right  charter discussion goes to the l3vpn and l2vpn lists,
rest of the ppvpn discussion goes to the ppvpn-list, sorry I misread.

/Loa

-- 
/Loa

mobile + 46 739 81 21 64
email: [email-masked]

---

From: Loa Andersson <[email-masked]>
Date: Tue, 27 May 2003 19:54:24 +0200

Hamid,

I think that is wishful thinking. I know that there are issues with
using bgp (kkompella) from several ADs including at least Alex.

Also, being adopted as a wg document is no gurantee that it will
go all the way to become an RFC much less a PS.

If I read your mail correctly you don't seem to think the is a
difference in the problem space they [v,k]kompella address, if this
is the case you'll have to make a very convincing argument to me
as a wg-chair to send both to IESG requesting that they are reviewed
to become PS. I don't see that argument, and I don't even see an
attempt to make that argument.

Note: I haven't discussed this with Rick or the ADs, so their opionions
might differ.

/Loa

-- 
/Loa

mobile + 46 739 81 21 64
email: [email-masked]

---

From: Yakov Rekhter <[email-masked]>
Date: Tue, 27 May 2003 11:23:25 -0700

Loa,

> using bgp (kkompella) from several ADs including at least Alex.

Just saying that "there are issues" isn't enough - "the several
ADs" who have these issues need to document them, and then discuss
it in an open forum (WG mailing list) to see whether these "issues"
are of any practical significance.

Yakov.

P.S. So far we've seen Alex raising the issues he has with using BGP,
and Pedro addressing them...

---

From: Alex Zinin <[email-masked]>
Date: Tue, 27 May 2003 12:22:28 -0700

Yakov,

> it in an open forum (WG mailing list)...

Agreed. This indeed needs to happen.

> to see whether these "issues" are of any practical significance.

> and Pedro addressing them...

I wouldn't call that "addressing". We rather have different opinions.

Alex

---

From: Alex Zinin <[email-masked]>
Date: Tue, 27 May 2003 12:24:15 -0700

Loa,

 I think we are in agreement.

-- 
Alex

---

From: Loa Andersson <[email-masked]>
Date: Tue, 27 May 2003 23:03:42 +0200

Yakov,

I don't have the power to require that IESG do or don't do anything.
What I can do is to send a specification to the IESG asking them to
review it and publish as an RFC, that is what any wg chair can do.

But I can send an humble request ;)

IESG,

the ppvpn wg group has an ID describing a solution for the L2VPN space 
based
on MP-BGP as a signaling protocol, and also an ID describing a VPN 
membership
discovery mechanism based on BGP.

We have been informed by our ADs that IESG have concerns relating to the 
use of
BGP in this context. To simplify the future work in the wg it would be
useful to have those concerns documented.

/Loa

PS

Is this "enough"?

-- 
/Loa

mobile + 46 739 81 21 64
email: [email-masked]

---

From: Alex Zinin <[email-masked]>
Date: Wed, 28 May 2003 00:31:56 -0700

Loa,

  I think it is indeed the right thing to ask the IESG
  to come up with clear formulation of the concerns.

  Consider me the token holder.
  Thanks.

-- 
Alex
http://www.psg.com/~zinin/