RE: Optical Link Interface

[Jonathan Lang <jplang@calient.net>]

Vasant,
  Please see inline comments.

Thanks,
Jonathan
>-----Original Message-----
>From: Vasant Sahay [mailto:vasants@nortelnetworks.com]
>Sent: Tuesday, July 31, 2001 8:18 PM
>To: Bilel Jamoussi; IMCEAMAILTO-fredette+40photonex+2Ecom@nt.com
>Cc: ccamp@ops.ietf.org
>Subject: RE: Optical Link Interface
>
>
>Andre,
>Bilel, Osama and I have discussed the LMP related extra-work with you in
our teleconference 
>a few months ago. 
> 
>The scope of LMP is much wider than just OLI. Before LMP gets accepted as a
standard, there 
>is a lot of functionality and requirements in LMP that have to be agreed
upon. Dependence 
>on LMP will only complicate and delay OLI. Besides, reliable transport of
failure-messages 
>is broken in LMP. The current LMP and WDM-LMP drafts imply that the
application will have 
>to build a mechanism for tracking and retransmitting lost messages. This
translates into 
>additional baggage for OLI. 
I think you're still confused.  Please look over our previous email
exchange.
 
>As an example LMP has ability to isolate faults. It is not needed for OLI.
You can argue 
>that you will reuse the same messages in OLI to report faults, but it is
not the same 
>thing. When LMP gets fully defined with states and procedures then we will
find that the 
>procedure for handling a failure message between two OXCs (LMP), is very
different than 
>that for between OXC and DWDM (OLI). As an aside my take is that
failure-isolation does not 
>even belong fully in LMP. It is a function that belongs between
connection-management and 
>link management.
Please reread the lmp draft before misrepresenting it.  The fault
localization procedure consists of a fault notification message and message
ack.
 
>There are more examples of extra work due to LMP but we can discuss them
one at a time.
I suggest you mention them; the TCP vs. LMP reliability isn't flying (e.g.,
see Spencer's email) this was also discussed in Minneapolis. 
 
>I did a quick back of the envelope and came up with a total of 24 states
and 46 events in 
>LMP. That is a lot of states for a simple protocol. This does not even
include the 
>application states for (potential) retransmission of messages.
>
>
>Cheers
>Vasant
>
From: Andre Fredette [mailto:fredette@photonex.com]
Sent: Monday, July 30, 2001 1:51 PM
To: Jamoussi, Bilel [BL60:1A00-M:EXCH]
Cc: John Drake; ccamp@ops.ietf.org
Subject: RE: Optical Link Interface


Bilel,

I might not have worded my response exactly as John did (being the nice guy
that I am), but I agree with his answers.

In particular, you continue to talk about "unnecessary LMP baggage", or
"complexity", but cannot describe what it is. 

Andre

At 01:24 PM 7/30/2001 -0700, John Drake wrote:


-----Original Message----- 
From: Bilel Jamoussi [mailto:jamoussi@nortelnetworks.com] 
Sent: Monday, July 30, 2001 8:14 AM 
To: 'Andre Fredette'; 'ccamp@ops.ietf.org' 
Subject: RE: Optical Link Interface


Andre, 
2 comments on you statistics, then a proposal to progress: 


1. The stats are not that significant, since there was no "last call" period
announced in advance to gauge community interest. 
[John Drake] 
This is silly.  Who else would you like to hear from? 
2. I do not think IETF uses company affiliation when measuring consensus. If
it did, then the fact that 3 from Nortel are supporting NTIP, is an
indication that there is an immediate need for NTIP given Nortel is a key
player in this space. 
[John Drake] 
The fact that you perceive yourself to be a key player shouldn't a priori
give your opinion any additional weight 
------ 


All, 


Now to focus the discussion back on the OLI solutions (NTIP or LMP-WDM, or a
merged version), 


- There is consensus on a single protocol which I respect. 


- Key distinctions between NTIP and WDM-LMP: 


1. WDM-LMP assumes that LMP is a priority, people will implement LMP, hence
WDM-LMP is a natural extension. The issues here are: 
(a) this assumption is not accurate, the functions of NTIP (or WDM-LMP) are
more urgent than LMP 
[John Drake] 
What is the basis for this assertion?   When we started the LMP-WDM work we
asked you to work on it with us 
and you refused, citing lack of need. 
(b) there is significant baggage to be carried from LMP down to the WDM-LMP 
[John Drake] 
You've made this assertion inumerable times, and have been asked inumerable
times to enumerate what this 
excess baggage is.  You have yet to do so. 
2. WDM-LMP assumes a peer model between the OXC and the WDM system. The
issue: 
- this model doesn't reflect the reality that OXC and WDM are two different
devices - the OXC-WDM relationship is client-server one. 
[John Drake] 
This is an assertion.  Some of the co-authors of the LMP WDM draft work for
WDM vendors and  they're happy with 
the peer relationship between the two devices   
I suggest merging the two proposals as follows: 


- remove unnecessary LMP baggage 
[John Drake] 
Once again, this would be what? 
- adopt a client-server model 
[John Drake] 
No 
- allow for TCP as the transport 
[John Drake] 
No one but you and your co-authors think that this is either necessary or
desirable 
- clarify a simplified autodiscovery mechanism 


Bilel. 


-----Original Message----- 
From: Andre Fredette [mailto:fredette@photonex.com] 
Sent: Thursday, July 26, 2001 2:52 PM 
To: ccamp@ops.ietf.org 
Subject: RE: Optical Link Interface 


 From my count on the mailing list we have the following results so far: 


LMP-WDM:  8 
NTIP: 3 (All from Nortel) 
Agnostic: 1 


And then there are the other 16 co-authors of LMP-WDM who haven't posted 
(perhaps because they don't think they have any new points to add). 


Andre 


At 02:00 PM 7/26/2001 -0400, Martin Dubuc wrote: 
>Kireeti, 
> 
>I have been following this thread with great interest. I agree with your 
>conclusion that we should pick one protocol and move forward. 
> 
>You are talking about WG reaching a consensus. I cannot see how this is 
>possible given the two very different views I see in the latest email 
>exchanges. 
> 
>How can we resolve the current dispute? What forum should we use to make 
>a final decision on this? 
> 
>Martin 
> 
>-----Original Message----- 
>From: Kireeti Kompella [mailto:kireeti@juniper.net] 
>Sent: Wednesday, July 25, 2001 9:57 PM 
>To: jamoussi@nortelnetworks.com; kireeti@juniper.net; 
>osama@nortelnetworks.com 
>Cc: bon@nortelnetworks.com; ccamp@ops.ietf.org; 
>vasants@nortelnetworks.com 
>Subject: RE: Optical Link Interface 
> 
> 
>Hi Osama, 
> 
> > Even though I don't think reviving CR-LDP and RSVP-TE history will get 
>us 
> > anywhere 
> 
>"Those who forget (ignore) history are doomed to repeat it." 
> 
>Yes, it makes for painful recollections.  We're living with the 
>consequences now, though, and I don't want to again. 
> 
> > the existence of two protocols here have proven to be useful. 
> 
>That's not what I'm hearing, either from customers, or from the 
>WG (admittedly, the sample is small). 
> 
>Listen carefully: I don't want LMP-WDM and NTIP moving forward. 
>Just NTIP (or NTIP and LMP) is OKAY if that is what the WG 
>consensus is.  LMP-WDM and LMP works too. 
> 
>So: you've got the WG chairs (scarred and grumpy), the ADs 
>and TA (speak up if I'm misrepresenting you), and customers 
>saying, Pick one protocol and move forward.  Let's do that. 
>And, please, as Vijay says, let's resolve this already. 
> 
>Kireeti.