[Ns-developers] Possible approaches to modelling optical pass through devices

[Tom Henderson]

On 03/11/2012 04:00 AM, Vedran Miletić wrote:
> Hi,
>
> I'm hoping to post somekind of repository with somekind of working
> optics, but I have to decide on this before proceeding.
>
> In optics there is a lot switch or hub-like devices with some kind of
> "pass through" property, i.e. device just forwards packets (better say
> signals but let's ignore this for now) in various ways. Some of them
> also have a control plane that understands IP routing and changes
> their state in accordance to messages exchanged with peers over IP. I
> see a couple of different approaches to modelling this. Let's see an
> example with modelling optical cross connect (OXC), which is some kind
> of a switch.

Can you comment more on the IP routing and addressing model that you 
have in mind?  Is this GMPLS-based (RFC 3945)?  Is it the case that 
these switches will make (dynamically) available, to IP-enabled nodes, 
some label-switched path (LSP) between the nodes?

Assuming that is the case, then my first impression is that you will 
want some kind of new NetDevice at the IP link endpoints, and you 
probably can model the switch and optical network itself however is most 
natural for you, because Ipv4GlobalRouting is not going to work over 
this kind of a dynamic optical switched network without modifications 
(and it is debatable whether it is within scope for global routing, 
which is intended for static topologies).  We may also want to consider 
MPLS support and its ns-3 design while we are defining this.

- Tom