Subject: RE: Single vs many solution(s)

From: "Vasile Radoaca" <[email-masked]>
Date: Tue, 6 May 2003 12:31:02 -0400

Vach,
 
              This is the culture that we build - did we built the
constrains before we started the selection vote?
              Do you think that showing hands in the ppvn group, at your
singular request was better then working
              via e-mails? Can you guarantee  a fair distribution of the
participants during your call?

          Vasile

-----Original Message-----
From: Vach Kompella [mailto:[email-masked]] 
Sent: Tuesday, May 06, 2003 12:14 PM
To: [email-masked]; [email-masked]; Radoaca, Vasile
[BL60:X624:EXCH]; [email-masked]; [email-masked]
Cc: [email-masked]
Subject: RE: Single vs many solution(s)

Richard,
 
Were you at the IETF in San Francisco?  Did you count the vendor/provider
support there?  There is an incorrect notion that just because a number of
"individuals who work for providers" have supported the BGP draft, that
there is provider support for it.
 
To continue this further: how would you evaluate the "support" an individual
who works for a vendor that does not have a box that even remotely can
perform L2VPN functions?  How would you evaluate the "support" of an
individual who works for a provider that is not remotely connected to the
department that would either make the decision to provide L2VPNs or
implement or support L2VPNs?
 
Individuals at the IETF cast their support as individuals.  If you want to
qualify it as vendor or provider support, then please take the extra step of
figuring out if they really speak for the company.  Thanks.
 
-Vach

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Tuesday, May 06, 2003 7:27 AM
To: [email-masked]; Vasile Radoaca; [email-masked];
[email-masked]
Cc: [email-masked]
Subject: RE: Single vs many solution(s)

Himanshu, 

I believe that there can exist multiple solutions for different sets
of problems. However, one must not confuse the solution with
signaling. We oughta not have two signaling mechanisms for 
two solutions to the same problem.

[RS: I agree that there should only be one 'functional specification'.
However, I don't think we can rule out the possibility of having to use more
than one protocol for each function until the functional specifications have
been developed.] 
 
A while back, it was determined that PW setup signaling is not
the charter of PPVPN but of PWE3. Lately, we have been 
discussing again whether BGP based signaling is better than LDP
based signaling. We have got to get past this issue once and for
all. My personal experience (having implemented BGP based 
signaling for L2VPN) is that my previous company could not find any customer

demand for BGP-based solution (we did not look into Italy though :-) 
However, there was greater interest in LDP based solution and
public forums to test interoperability with.

[RS: Carrying out a quick count of the individuals that have expressed
support on this mailing list for the two opposing drafts (K.Kompella vs.
V.Kompella/Lasserre), based on whether they work for an SP or a vendor the
results are (roughly):
 
Draft     Vendor Support    SP Support
BGP              4                      19
LDP               7                       3
 
These results would suggest that customers (i.e. SPs) prefer the BGP
approach. I am not saying that I agree, far from it, but I don't think that
we should rule out protocols at this stage, especially in the inter-AS case.
Instead we should be focussing on getting the functional specifications
correct.]
 
I think we have learned enough lessons from CR-LDP vs RSVP-TE
debacle. Lets not repeat it for L2VPN.
 
...Richard 

 
 -----Original Message-----
From: Vasile Radoaca [mailto:[email-masked]]
Sent: Monday, May 05, 2003 11:21 PM
To: 'Alex Zinin'; [email-masked]
Cc: Yakov Rekhter
Subject: RE: Single vs many solution(s)

Alex, 

  I think the ideal goal is to have only one solution, but such ideal usual
can be achieved if we are working in a pure theoretical environment, without
market considerations. In reality the market is driving in most of the
cases, and some assumptions made two years ago are not any more valid -
there are categories of SPs that pretty much have disappeared from the map.

  You stated very clear that a problem space needs to have a single
solution. I fully agree with you as a goal, but ut the issue that we face
right now is that the problem space is not well concluded and well
understood just purely from technical considerations. 

 The L2 VPLS is a complex space with multiple dimensions, and the vendors -
in the last two years -  have worked from different angles, optimizing one
or more dimension(s) of the problem space (probable the downturn in the
market it self, was part of the problem). Without to contradict each other,
most of the solutions are closed in a specific dimension, based on some
objective/subjective parameters or experience and some criteria of
optimization. Moving in only one dimension doesn't scale it self.

 The fact we do have more than one solution, I think is a good thing, and
doesn't contradict that we can't move toward one solution, if we are driving
diligently, and willing to make compromises. Taken such research value in
consideration, would be a positive sign that IETF is looking to create a
solution that would be valid for a while. Reading the mailing list, I
observed the same wise advise from most of the SPs, and this reflect not a
"problem" but a reality.

Cheers 
   Vasile 
  
-----Original Message----- 
From: Alex Zinin [mailto:[email-masked] <mailto:[email-masked]> ] 
Sent: Monday, May 05, 2003 5:27 PM 
To: [email-masked] 
Cc: Yakov Rekhter 
Subject: Single vs many solution(s) 

Yakov, 

[I took the liberty to change the subject line] 

>> I believe the goal for the WG should be to work out 
>> a single solution. 

> That is certainly not in the charter. In fact the goal 
> you stated above directly contradicts what is in the charter: 

>    Multiple approaches are being developed as each approach 
>    has particular characteristics and differing scope of 
> applicability. 

Thanks for pointing out a possible contradiction. I don't think it exists. 

My opinion (and I think it would be safe for me to say it is consistent with
that of the IESG) is that as long as different solutions are solving
different problems (or, as the text of the charter says, have different
scopes of applicability), it is fine to have more than one solution.
However, for a single problem, we only need a single STD'ized solution.

> And if you believe that for VPLS the goal should be a single solution, 
> then why wouldn't you insist to have the same goal for L3 VPNs ? 

you forgot to add "and if you wouldn't insist on a single solution for L3
VPNs, then why do you insist on this for L2 VPNs" ;-)

The reason is I don't want to restart the L3 VPN work in the IETF and/or
revisit the decisions that have been made in the past, while I still see a
reasonable opportunity to steer the L2 VPN work.

> Also, if you insist on a single solution, wouldn't that 
> imply a single auto-discovery mechanism for VPLS ? 

This would definitely be my preference. 

Alex

---

From: Alex Zinin <[email-masked]>
Date: Tue, 6 May 2003 10:57:21 -0700

Vasile, Vach, et al-

  I suggest we drop the subject of 'votes' and 'counting' right here.

  This could have been an interesting discussion some other time,
  but now it is distracting.

  At the end, gauging and declaring consensus is the responsibility of
  the WG chairs, so let them do their job.
  
-- 
Alex