Re: [CCAMP] Fwd: I-D Action: draft-berger-ccamp-swcaps-update-00.txt

[John E Drake <[e-mail]>]

Snipped, comments inline

> 
> Given that maturity level of this (our) draft, I would not recommend
> any
> changes to gmpls-ospf-g709v3 at this time.
> 
> That said, if you want to use gmpls-ospf-g709v3 as an example, ILH
> would
> be set to match the Signal Type of the #stages=0 TLV carried in the
> ISCD/SCSI.  As I read the gmpls-ospf-g709v3, gmpls-ospf-g709v3 already
> precludes the advertisement of different Signal Type at the #stages=0
> in
> the same ISCD, so there would be no change in number of advertised
> ISCDs
> due to the use of ILH field in this example.
> 

[JD]  This is the same problem I have had all along.  Viz, you are explicitly equating trunk bandwidth with layer boundaries.  

I have yet to hear anyone articulate why this is necessary or useful, and even if it were necessary or useful, advertising an explicit field is duplicative because we *already* advertise trunk bandwidth, and hence in this formulation, layer boundaries.  If an implementation were to decide that having an explicit field was necessary or useful, it could easily be included in their internal data structures without cluttering the advertisements.

As an aside, PSC 1-4 did not do this.  Instead, PSC 1-4 was an entirely logical concept, which meant that the network designer could place the layer boundaries wherever they wished.

Thanks,

John