RE: GMPLS signaling documents updated per last calls

["Mannie, Eric" <Eric.Mannie@ebone.com>]

Hi Stephen,

The current wording is (as it is written in the updated draft that I sent
last week on the ccamp mailing list):

"A SONET signal which has an identical SDH signal SHOULD be requested using
the same traffic parameters as for the equivalent SDH signal, and will
consequently use the SDH label."

We spend with Maarten a lot of time to write that sentence (not easy to
write).

Maybe that it should be better written:

"A SONET signal which has an identical SDH signal SHOULD be requested as an
SDH signal using the same traffic parameters as for the equivalent SDH
signal, and will consequently use the SDH label."

This means in practice: request an SDH signal when identical to a SONET
signal. In that case, from the control plane point of view everything is
SDH, i.e. the control plane is not aware of SONET at all. Of course, if an
SDH signal is requested the SDH label is used. The distinction between SDH
and SONET in that case being only at the connection monitoring level if I am
right (please confirm).

This doesn't mean that the SONET signal format disappear (simply not used in
that case), for backward compatibility we need to keep it.

Kind regards,

Eric


-----Original Message-----
From: Stephen Trowbridge [mailto:sjtrowbridge@lucent.com]
Sent: Tuesday, December 18, 2001 7:46 PM
To: Kireeti Kompella
Cc: ccamp@ops.ietf.org; dbrungard@att.com; lberger@movaz.com;
bwijnen@lucent.com; sob@harvard.edu
Subject: Re: GMPLS signaling documents updated per last calls


Kireeti,
The one outlyer is VT3 (3 Megabits). VC-3 is an extremely popular
rate in both SONET and SDH. I exchanged an email with Deborah Brungard
(T1X1.5 chair) on this one and I take the liberty of sharing her response:

Deborah Brungard wrote:
> The VT3 (3M) structure was defined - but no services (mappings) were ever
defined for it. So there are no services/equip
> with it. My take was if in the future it was ever defined (doubtful), we
would be adding it to g707 also. So then it
> would just be part of g707 too.

So basically, there are no mappings or equipment functions for this rate,
and as far as we know no network equipment or networks supporting it.
Deborah suggests that if we were ever to define such mappings, that this
would be proposed for addition to G.707 and hence be part of SDH.

I think our agreement had been to use the SDH label for all signals that
had the same multiplex structure in SONET and SDH. In Salt Lake City, we
thought
that this was everything except VT3. Given that VT3 seems not to be a "real"
signal at this point and will likely be added to SDH if it ever becomes
real, does our agreement then become that we use SDH labels for everything?

Regards,
Steve

Kireeti Kompella wrote:
> 
> Hi Deborah,
> 
> > I previously made the
> > comments to merge the (1) SDH and SONET values as one value
> 
> There was a meeting among Steve Trowbridge, Maarten Vissers,
> Eric Mannie, Dimitri Papadimitriou, the CCAMP ADs and chairs on
> several issues, among them this one.  The upshot was that whenever
> possible, the SDH label should be used, with the encoding type
> set to SDH (i.e., G.707); however, there are signals that have
> no SDH equivalent (if I remember right, VC-3 -- someone correct
> me!), so we will keep SONET labels and encoding types around
> for that case and for legacy equipment.
> 
> The revised SONET/SDH document will contain the exact wording.
> I will also be sending a reply to the ITU communication stating
> the agreement we came to.
> 
> Kireeti.