Subject: RE: Optical IP activities

From: "Peter Ashwood-Smith" <[email-masked]>
Date: Fri, 17 Mar 2000 18:17:45 -0500

> I am sure you can abstract physical limitations/properties and use
the as
	> constraints in routing algorithms. The real issue here is whether
you
	> want
	> all the routers to know about these "optical constraints"
	> (distortion/chirp,
	> wavelength conversion capability). The other option would be to
keep
	> these
	> two domains separate and use an abstraction where the routers view
the
	> optical 
	> network as a cloud (overlay model). I'm not sure which one is the
better
	> approach
	> and think that we need a better understanding of the optical
networks
	> and their
	> specific requirements to make that determination.

The argument you are making applies equally well to all forms of Path
Oriented Routing regardless of the switching technology they employ to form
a path. Therefor, by your logic, Path Oriented and Connectionless routing
systems should not be mixed but isolated and overlayed.

The above argument goes contrary to what MPLS is all about (bringing Path
Oriented Routing capabilities into IP) and against the operational
experience of many existing proprietary networking protocol systems. MPLS is
just a standards based expression of the lessons that have been learned over
the last 5-10 years in non standard systems. Optics is not really special,
its just really fast with a few new interesting constraints many of which
will disappear within a few years.

Cheers,

Peter

---

From: Debanjan <[email-masked]>
Date: Fri, 17 Mar 2000 18:36:15 -0600

> Peter Ashwood-Smith wrote:
> 
>> I am sure you can abstract physical limitations/properties 
>> and use the as constraints in routing algorithms. The real 
>> issue here is whether you want all the routers to know about 
>> these "optical constraints" (distortion/chirp, wavelength 
>> conversion capability). The other option would be to keep 
>> these two domains separate and use an abstraction where the 
>> routers view the optical network as a cloud (overlay model). 
>> I'm not sure which one is the better approach and think that 
>> we need a better understanding of the optical networks and their

> The argument you are making applies equally well to all forms 
> of Pat Oriented Routing regardless of the switching technology 
> they employ to form a path. Therefor, by your logic, Path Oriented 
> and Connectionless routing systems should not be mixed but isolated 
> and overlayed.

I am not making that argument at all. All I'm saying is that optical
networks
have special requirements and we need to understand them better before
deciding if we should use peer model or overlay model. May be we should
have both.

> Optics is not really special, its just really fast
> with a few new interesting constraints many of which 

Why do you think that the constraints will disappear within a 
few years? 

Regards,
Debanjan