DWDM Optics cheaper than CWDM Optics?


fs.com offers DWDM optics that are cheaper than CWDM optics:
CWDM 80km 10G for 600$ http://www.fs.com/c/cisco-cwdm-sfp-plus-2425?70-80km
DWDM 80km 10G for 420$ http://www.fs.com/c/cisco-dwdm-sfp-plus-2485?70-80km

This is significant.
Is this for real? Has anybody bought their DWDM optics?

Going with DWDM and passive Mux/Demux seems to be cheaper nowadays than going with CWDM.



I've bought at least 20k in optics from them in the last 2 years, from QSFP DAC, QSFP to 10g breakouts and everything in between and the only thing to fail was 1 QSFP breakout cable. A partner of ours uses their DWDM optics and passive MUXs while I've used their CWDM with no issues.

Luke Guillory
Network Operations Manager

Tel: 985.536.1212
Fax: 985.536.0300
Email: lguillory@reservetele.com

Reserve Telecommunications
100 RTC Dr
Reserve, LA 70084

I have been under the impression for years now that the age of the fiber
may play a roll in which you prefer due to channel spacing needed to cram
in more frequencies. Never really came across a real world situation where
one didn't work as well as the other. There is probably more things to
consider than the fiber's age.

Thank You
Bob Evans

I came to the same conclusion a couple years ago. At the time, CWDM was about the same price as DWDM or maybe still just a hair cheaper, but the DWDM system is a) so much more capable, and b) typically has better tools/monitoring, etc. (if you're using muxponders, etc.) that it made sense to just go DWDM. Given advances in optics, I'm not surprised that DWDM is now cheaper than CWDM outright.

Of course, the same may not be true if you're buying a fully engineered system from a major vendor. CWDM can be a little easier to engineer...sometimes.

Since I am in the middle of doing something similar, I will share my observations.

CWDM Advantage:-
     Passive CWDM Muxes are less expensive than the DWDM counterparts.
     Short Range optics (CWDM) are favorable priced
     Long Range optics are not so favorably priced.
      ( I guess that is due to production volume).

Deploying a CWDM passive mux solution, can allow you to stack a DWDM mux on the 1530-1560 CWDM channel.
(one has to pay attention to the loss/attenuation calcs).

If you need to Regen the light.. then there are a lot of solutions (cost effective) available for the DWDM channel range
(have not been able to find any kind of amps for CWDM.. if anyone has suggestions, I would be open to them).

Amount of channels available on CDWM are limited in qty when compared to what is possible with DWDM.

When using long rage optics, pay attention to the equipment you are plugging them in.. not all optical ports are capable of supplying the amount of power and heat dissipation required.

As to the original question about the quality of optics from FS.COM..
We have no complaints, when there were mistakes made, they stood behind their products and corrected them.
I would recommend that you deal with one of their many Sales Rep's vs just placing order online.

Their products match the specs they list.. They are also able to do some custom stuff which is not listed on their web site..
(i.e. provide muxes which have a lower insertion loss in certain configurations).


Faisal Imtiaz
Snappy Internet & Telecom
7266 SW 48 Street
Miami, FL 33155
Tel: 305 663 5518 x 232

Help-desk: (305)663-5518 Option 2 or Email: Support@Snappytelecom.net

Just so you know, FS.com now stocks many of the common optics in Seattle
Washington for next day delivery. So they now are stocking more and more
items in the USA.

When we order an item from China on Monday USA time, we get it it Thursday
morning USA time if its in stock in China!

I've bought their DWDM 80km 10gig and they are working beautifully on
a couple amplified circuits with both Cisco and Juniper routers. I've
also bought gray optics and DACs. The only issue I've noted with some
QSFP+ DACs is some kind of programming issue where the serial number
is mis-read by some models of our Juniper switches. Another oddity is
that each end of some of our DACs have a separate serial number...we
just record both in our inventory tracking system.