North American Network Operators Group

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Re: DWDM interconnects

  • From: Barton F Bruce
  • Date: Mon Jan 06 19:14:05 2003

DWDM comes in many flavors, and I doubt it makes much sense to hand another
carrier a fiber with a lot of different lambdas on it (if that is what you
were asking). There are way too many variables.

OTOH, if you were simply refering to buying the use of one "wave" (or
"lambda") that is a normal product for many companys. Unlike dark fiber,
they have lit the route and are just selling you a lambda off their big DWDM
system. They may choose to price it differently if you are running OC192 on
it than if you are running OC48, bit in any case the Sonet ADM gear is up to

Your connection is very apt to be a short range 1310 into them and their
DWDM gear then will convert it to an ITU grid color up in the 1550 range and
will coordinate signal levels, etc to eliminate crosstalk with adjacent
channels. All you can mess up is your traffic.

Lambda sales will become even more popular at major optical switching
centers as realtime open markets evolve.

Finisar is finally about to ship GBIC shaped pluggable optical devices in
ITU grid colors. They will have actually, I think, two speed ranges, one for
OC3 and OC12 and the other one for GIG-E and OC48. The exact application
depends on the card you plug this generic device into. First big batch
samples this month, and full production maybe April.

The SFP (Small Formfactor Pluggable) units won't be getting ITU grid colors
for over a year later.

Finisar has been armtwisted into protecting the largest router arrogance,
especially in the 80km GBIC product space. In the more plebian range down at
the 10 km 1310 units or the local MultiMode units you will find more price
competition and should pay respectively less than $200 and $100 even in
small quantities. Molex doesn't make 80km units but does make the rest, and
cisco as well as everyone else buys from both. Don't ever say whose
equipment you are go to use a GBIC with, because they then may not sell it
to you! The DOJ has to fit in here somewhere.

On a metro area scale, I bet someone might sell you a lambda on a passive
DWDM network  to some building where your service didn't compete with
theirs, and where you were using the same power same brand pluggable "GBIC"
like devices and where there was no chance for your messing up their
adjacent channels with too hot a signal. These pluggable devices will open
up many options.

But the long haul intelligent DWDM systems are juggling way too many
variables and should be under one company's management. There is too much at
risk and too easy to screw up.

Of course two carriers can and will do whatever they want between
themselves. We were the first carrier to drag an RBOC into an
interoperability test with our cisco/cerent 15454s and their whatever. Cisco
had not been certified til then to interconnect to any RBOC and was very
eager. VZ, well, they did it because the letter from their legal dept said
to. They used the Fugitsu FLMs in various sizes to test against just one
Cerent using its wide range of cards. Now VZ is using Cerents themselves.

After the grief we went through to get simple RBOC OC3, OC12, and OC48
interconnections blessed, I would hate to try adding DWDM to the mix.

----- Original Message -----
From: "Pete Kruckenberg" <[email protected]>
To: <[email protected]>
Sent: Monday, January 06, 2003 6:04 PM
Subject: DWDM interconnects

> How common are DWDM interconnects between networks
> (carriers)?
> Is DWDM considered a reliable/scalable/operable carrier
> interconnection technology?
> Is multi-vendor DWDM (whether internal to the network or for
> carrier interconnection) practical or sensible, especially
> for carrier/network interconnection? Many vendors proclaim
> interoperability, but does that work in the real world?
> Pete.