Re: Routed optical networks

[Jared Mauch <jared () puck nether net>]

> On May 2, 2023, at 2:29 PM, Etienne-Victor Depasquale via NANOG <nanog () nanog org> wrote:
>
> On Mon, May 01, 2023 at 02:56:47PM -0600, Matt Erculiani wrote:
> > In short, the idea is that optical networks are wasteful and routers do a
> > better job making more use of a network's capacity than ROADMs. Take the
> > extra router hop (or 3 or 8) versus short-cutting it with an optical
> > network because the silicon is so low-latency anyway that it hardly makes a
> > difference now. Putting more GBs per second on fewer strands means saving a
> > lot of money on infrastructure costs.
>
> This is a very convoluted way of backing into the ole packet-switched
> vs. circuit switched decision.
>
> I don't follow. 
> While ROADMs can be thought of as circuit-switchers,
> the number of concurrent clients and switching latency put ROADMs on a different operational level than packet 
> switchers, right?


I’ve seen proposals for an LSR MPLS/ROADAM type solution, where imagine you are at a hop where in a long distance 
system solution, you would end up with OEO, but instead you get directionality capability with an IP/MPLS capable 
device.  As mentioned previously, the 400-ZR/ZR+/ZR-Bright/+0 optics are the latest example of that.

I know of a few companies that have looked at solutions like this, and can expect there to be some interesting 
solutions that would appear as a result.  Optical line systems tend to have pretty low power requirements compared to a 
router, but some of the routers are getting pretty low power as well when it comes to the power OPEX/bit, and if you 
have the ability to deliver services as an integrated packet optical you could see reduced costs and simplified 
components/sparing.

I’ll also say that I’ve not yet seen the price compression that I had expected in the space yet, but I figure that’s 
coming.  We are seeing the bits/watt ratio improve though, so for the same or less power consumption you get more bits. 
 Some of this technology stuff is truly magical.

- Jared