Subject: Re: draft-raggarwa-rsvpte-pw-01.txt

From: Kireeti Kompella <[email-masked]>
Date: Wed, 23 Mar 2005 11:48:44 -0800 (PST)

On Wed, 23 Mar 2005, Bruce Davie wrote:

> I don't think it's helpful for the WG to propose another protocol for PW
> signalling before it has even finished standardizing the first one. Maybe
> when we have some consensus on the requirements for multi-segment PWs we'll
> decide that we need something beyond LDP and L2TPv3, but we're not at that
> point yet.

I agree that gathering and nailing down the multitude of new reqts
(MH, QoS/CAC, BW, ...) is necessary.  Given that, it seems premature
to pass judgment on RSVP, or to state that another protocol is
redundant.  (It is equally premature for me to state my support, but
what the heck.)

For that matter, it's not like we have a single PW protocol.  The
"unhelpful" event already occurred, for better or worse.  Now we
should focus on what's the most suitable protocol for the reqts.

>  So, at this time I oppose making this a WG draft.

Does that mean you may change your mind once you see the full gamut of
requirements, and the choice devolves into (a) upgrading LDP to CR-LDP
or (b) adding PW support to RSVP-TE? :-)

Kireeti.
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From: Bruce Davie <[email-masked]>
Date: Wed, 23 Mar 2005 17:02:40 -0500

--On Wednesday, March 23, 2005 11:48 AM -0800 Kireeti Kompella 
<[email-masked]> wrote:

>> when we have some consensus on the requirements for multi-segment PWs
>> we'll decide that we need something beyond LDP and L2TPv3, but we're not
>> at that point yet.
>

I haven't passed judgment on RSVP. It certainly seems premature to start 
increasing the number of protocols for PWs before we agree on the 
requirements.

> should focus on what's the most suitable protocol for the reqts.

Once we have the reqts, I agree.

> or (b) adding PW support to RSVP-TE? :-)

I chose my words carefully. By saying "at this time" I do indeed mean that, 
when we have a better sense of the requirements, it would be a good time to 
decide which protocol(s) the working group will adopt to meet them.

Bruce

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From: Kireeti Kompella <[email-masked]>
Date: Thu, 24 Mar 2005 13:02:23 -0800 (PST)

Okay, I said it.  Here they are:

Step back from the whole discussion a moment and consider the
following.

You want to create an end-to-end PW.  You have lots of PSN tunnels,
but you don't have any one PSN tunnel that gets you there.  So, you
have to pick "switching points" across the network(s).  Between a pair
of consecutive switching points, you may have a choice of PSN tunnels;
you may want to choose among them based on QoS, b/w, class-of-service,
....  You may want to do admission control on a hop (oops) PSN
tunnel-by-PSN tunnel basis.

You may further want to protect against the failure of a PSN tunnel,
or of a switching point.  Finally, you may have to cross ASes.

Can you think of any protocol that lets you:
a) carry the sequence of switching points that you wish to traverse
   across a network;
b) signal information about QoS or such-like properties;
c) perform admission control on a hop-by-hop basis;
d) set up alternate paths to deal with failure;
e) signal across AS boundaries?

View the PSN tunnels as links, a la LSP hierarchy or, if you wish,
G.805.  Then look again.

Kireeti.
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From: Kireeti Kompella <[email-masked]>
Date: Thu, 24 Mar 2005 12:45:13 -0800 (PST)

> > On Wed, 23 Mar 2005, Bruce Davie wrote:
...
> increasing the number of protocols for PWs before we agree on the

Good to hear that.

However (believe it or not), the authors didn't propose the above
document solely for the purpose of increasing the number of PW
protocols.  Thay have what they believe are sound technical and
pragmatic reasons.

> Once we have the reqts, I agree.

When do we "have the reqts"?  When:
a) it's a WG doc?
b) it's in WG Last Call?
c) it's in IETF Last Call?
d) it's an RFC?

> I chose my words carefully. By saying "at this time" I do indeed
> mean that, when we have a better sense of the requirements, it would
> be a good time to decide which protocol(s) the working group will
> adopt to meet them.

Same question as above: when can we say that we have a better sense of
the requirements?

Kireeti.
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