Re: Suggested Label Doubt

[Yangguang Xu <xuyg@lucent.com>]

Eric,

I was about to keep quite... Because of recent discussions, here is my comments
to your previous example in-lines. 

I am OK with current suggested label, label set etc. However I want to figure
out the real application in circuit switching network and please help me about
it. Thanks a lot.


[snipped]
> > >
> >
> > Would you please give me an example that what I said is not true?
> 
> 
> Local significance - not every switch in an optical domain is necessarily
> capable of performing the same kind of "optical switching".  This does not
> mean that they cannot interoperate - but it does mean that they may not
> interoperate in the way that you expect.  

Can you give me an "example", I mean a real one? Please specify what type of
circuit switches you are talking about, what's their functions etc. I have heard
too many hyperthetical applications that don't exist at all.

> Under these circumstances, the
> choice of "label" may have greater than local significance.  

Then that's routing constrains and you can specify certain routing constrains at
the signaling time. Label itself only has local significance.

> Moreover, you
> cannot end up lambda switching two light beams of the same color into
> a single piece of glass.

If you don't have any type of multiplexing mechanisms. It doesn't matter they
are the same color or not.

Otherwise, indeed you can, and it depends on your multiplexing and modulation
mechanisms (. You are probably only talking about wavelength multiplexing. For
that specific case, you may be right.

Sorry, this is just a side topic.

> 
> Upstream/Downstream indifference of choice - true in optical networks (at
> least "Normally"), but not particularly relevant.  One or the other MUST
> have the final say and the model to-date has been that the final word is
> given by the downstream.  Given that there MAY BE a scenario in which one
> or the other has less than complete knowledge, it is necessary to have a
> negotiation/arbitration mechanism.
> 

I think the upstream/downstream nodes are symmetric in circuit switching
network. I am looking an example to show me that your "MAY BE" is true.

BTW, I have concern about the definition of upstream/downstream. Their
definitions in RFC 3031 need modifications for GMPLS.

Thanks,

Yangguang