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RE: Optical Link Interface - Correction
Bala,
Yes, I counted you as "agnostic" in the LMP-WDM vs. NTIP debate, though I
do know that you think the OLI is important and you care that the solution
is a good one. I also agree (as I've stated before) that either LMP-WDM or
NTIP could be made to work. I just believe that having the group focus on
one protocol rather than two will have a better end result and aid in wider
deployment.
I'd also be glad to work on streamlining LMP-WDM.
As I see it, the basic requirements are the same for both LMP and OLI for
the following:
1. Control Channel Maintenance (A.K.A. a light weight hello protocol).
2. The ability to exchange information on links (link summary, perhaps with
a few different TLVs)
3. Discovery/Test. (Note: The main purpose here is for two devices to agree
on ID's for each link so information exchange regarding the links is
possible. The only reasonable way it is possible to automate this, is to
send some type of test messages on the physical links). To do this,
you need to be able
to terminate the links.
4. Fault Notification (By the way, I think the ChannelStatus Message
defined in LMP-WDM
could replace the current ChannelFail Message in LMP)
5. Notification whether a link is in use (ChannelActive Message).
Because of this we have proposed basing the OLI on LMP.
If these features need streamlining for LMP-WDM, they probably also need
streamlining for LMP, so let's fix them once.
If there are other LMP-WDM-specific procedures that need to be streamlined,
I'm all ears.
The major difference I see is that LMP needs is the ability to manage link
bundles for the purpose of routing advertisements, but the OLI doesn't. In
the LMP-WDM case, I was expecting we'd usually have a single link bundle
(effectively ignoring this feature of LMP).
Regarding the discovery portion of LMP (i.e., "link connectivity
verification"), from a protocol standpoint, it should work. It does
require that the PXC be able to terminate each port with an appropriate
interface (from LMP: "For the LMP Test procedure, the free (unallocated)
data-bearing links MUST be opaque (i.e., able to be terminated)"). The PXC
would need to support termination of the various types of ports that could
be used (e.g., SONET, SDH). But, this is more of a hardware requirement
than a protocol requirement.
Andre
At 09:36 AM 7/27/2001 -0400, Bala Rajagopalan wrote:
>Forgot to attach the new NTIP draft.
>Also, I meant "working on (4)", not (3).
>
>
>Bala Rajagopalan
>Tellium, Inc.
>2 Crescent Place
>P.O. Box 901
>Oceanport, NJ 07757-0901
>Tel: (732) 923-4237
>Fax: (732) 923-9804
>Email: braja@tellium.com
>
> > -----Original Message-----
> > From: Bala Rajagopalan
> > Sent: Friday, July 27, 2001 9:28 AM
> > To: 'Andre Fredette'; ccamp@ops.ietf.org
> > Subject: RE: Optical Link Interface
> >
> >
> > Andre:
> >
> > I believe you're counting me in the "agnostic" category.
> > I hope this is not taken as "don't care", since I
> > do have an interest in making a choice quickly.
> >
> > I have looked at the LMP-WDM draft (again) and the new
> > NTIP draft sent by Osama (attached). I see the following:
> >
> > 1. Both these solutions gloss over the details of
> > auto-discovery between OXCs and WDM. (Note: the
> > issues are the same regardless of the protocol used
> > and neither provides full details. Furthermore,
> > the hardware requirements and actions under both
> > are the same).
> >
> > 2. If we leave out (1), then the other functions are
> > based on messaging over the control channel
> > between the OXC and the WDM. This messaging
> > can be done one way or the other.
> >
> > 3. Both require control channel maintenance using
> > (simple) keepalive.
> >
> > 4. It seems LMP-WDM can be streamlined to make it
> > more lean and mean.
> >
> > Unless there is a significant technical issue
> > of one choice over the other, we have to consider
> > the fact that LMP-WDM has the first mover advantage.
> > Is it possible for
> > the NTIP proponents to seriously consider working on
> > (3)? Specifically, focus LMP-WDM on OLI requirements
> > only and not carry any unrelated LMP concepts into
> > LMP-WDM. Would this satisfy the design motivation for NTIP?
> >
> > Regards,
> >
> > Bala
> >
> >
> > Bala Rajagopalan
> > Tellium, Inc.
> > 2 Crescent Place
> > P.O. Box 901
> > Oceanport, NJ 07757-0901
> > Tel: (732) 923-4237
> > Fax: (732) 923-9804
> > Email: braja@tellium.com
> >
> > > -----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.
> > >
> >
>
>