The future of transport in the metro area

Fri Aug 2 20:10:32 UTC 2019

On 2/Aug/19 20:06, Etienne-Victor Depasquale wrote:
> Bear with me one more time as I drill down a little and spell things
> out. I've realized that there may be more than one interpretation of
> "EoDWDM". Are you referring to:
>
> (a) Ethernet packets in OTU frames - thereby implying an underlying OTN?
>
> (b) Ethernet optical SFP+ transceivers with a cable connection into a
> transponder plugging into a DWDM Mux or DWDM OADM? (no circuit transport)

Either one would count as EoDWDM, in my book.

The general use-case for OTN is to have SDH/SONET-like OAM
characteristics, but over the DWDM network.

In basic deployments, there was a time when folk argued about whether
they take LAN-PHY or WAN-PHY EoDWDM services from providers. The OTN vs.
DWDM discussion kind of falls around there, in my opinion. Considering
that almost all use-cases for EoDWDM are into router ports, where basic
day-to-day Ethernet is the cheapest and simplest option, I haven't heard
of any customers asking for WAN-PHY or OTN in the last 3 years. Not on
our network at least, anyway...

I think the costs of WAN-PHY/OTN re: OAM have been outweighed by making
the right choice in choosing an operator that is able to deliver an SLA,
back it up, and have a NOC that works well.

Now, the next step in all this that is starting to gain a bit of
traction is "spectrum", i.e., rather than take a normal grey service
from a Transport operator, have them deliver you a portion of the DWDM
spectrum so that you can run as much bandwidth as you want over their
network. Think of it as dark fibre, but lit...

Mark.