Re: [CCAMP] Generalized Labels for the Flexi-Grid in LSC Label Switching Routers

I think I see a general set of agreements coming along.

Appendix V.1 gives an example of needing 9 bits to encode m.
Although an Appendix is not part of the normative spec, we might assume two things from this appendix:
1. Currently only up to 8 bits are needed
2. The is a trend toward more than 8 bits

As Gabriele suggests, 16 bits is a lot. So I don't think we need to worry about extensibility if we go there.

I will update the I-D to make m 16 bits wide, and I will (continue to) say that the definition of m is per the slot width formula defined in G.694.1. This makes no comment within the draft on the legitimate values of m, but defers the data plane specification to the ITU-T.

As to describing such things in the framework, I would be opposed to an IETF document that describes the flexi-grid data plane in any detail. That is, IMNSHO, not our remit and not the scope of CCAMP. But we could ask the AD for an opinion on that ;-)

A

> -----Original Message-----
> From: CCAMP [mailto:ccamp-bounces@ietf.org] On Behalf Of Huub van Helvoort
> Sent: 03 February 2014 14:26
> To: Ramon Casellas; Oscar González de Dios
> Cc: CCAMP
> Subject: Re: [CCAMP] Generalized Labels for the Flexi-Grid in LSC Label Switching
> Routers
> 
> Hola Ramon,
> 
> G.694.1 does not define a maximum value for "m".
> 
> However G.697 gives in Appendix V.1: Wavelength ID.
> "m" = 9 bits (m is encoded as a 9-bit unsigned integer).
> 
> Regards, Huub.
> 
> 
>  >> I am happy if we don't need to do so. But is this not better than
> >> defining/ extending a new label format when ITU-T changes the data plane?
> >
> > Dear all,
> >
> > I may be missing something (apologies in advance if it is the case) and
> > since I don't have them here right now, for the sake of this discussion,
> > maybe could anyone point to the relevant part of the document(s) e.g.
> > G.694.1 / G.872 etc. where it is said that the value of m is bound to 256?
> > We are aware of the concept of frequency slot, nominal central
> > frequencies (n, and their values) and the concept of frequency slot
> > width, but I cannot recall now such a bound.
> >
> > Thanks
> > R.
> >
> 
> 
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