80 km BiDi XFPs

Is anyone aware of a reputable supplier of 80 km BiDi XFPs? My regular
supplier of generics doesn't have an option for us, but I would really like
to avoid leasing additional fibers.


Closest I've seen is 60km. I would be interested to hear if someone knows
of an 80km option.


I'm looking at a data sheet from Transition Networks that lists 80 km
(24 dB) and longer. I've used some of their SFPs and media converters
without trouble, but not these in particular.



already in production for 2 links

I'm going to guess that this is not going to meet the OP's request for an XFP, which would be 10GbE (and not an SFP).


How much spare margin do you have? Could you roll your own with a pair
of mismatched (C|D)WDM XFPs and a mux on each end?

Probably a safe guess. Mea culpa.

Check out Integra Networks. Their catalog lists a 10G XFP Bi-Dir



Thank you -- this is the first hit I've received. Thanks for all the others
who offered help, but all the other pointers led to 40 km or 60 km products,
1G SFPs, or stand-alone passive muxes.


How much spare margin do you have? Could you roll your own with a pair
of mismatched (C|D)WDM XFPs and a mux on each end?

Typically you have 23dB powerbudget for the ZR (CWDM or DWDM) - maybe +2 dB through selection of TOSA. A CWDM Mux will take 2dB and a small DWDM Mux approx. 4dB - you need two of them. This will drag your overall link-powerbudget below 20dB.

It might work if you add a FEC (either on the linecard or the XFP itself). This will add approx. 5dB to your powerbudget of 23dB. Take a CWDM Mux and fire x-crossed on 1550 and 1570 (maybe 1530) and you will face an attenuation of approx. 0,2 - 0,25dB/km. This could work and you should be able to transmit 80km to 90km. It's worth a test - also to figure out if dispersion will have an impact or not.


If you're going to that effort buy a mux with an amp, and use short-haul
SFP's with FEC.

A choice I found particularly neat (I got a hold of some of their HW
architecture docs but haven't actually tried it) is the SmartOptics
"m:series", an 4/8/16/32ch PTP metro DWDM system in a 1ru box (or 2ru
for 8/32ch)


MRV, BTI and others make more modular options if you want just the EDFA's.

Thanks, using an external CWDM mux is an option we're explorering.


Le 03/04/2013 01:15, Frank Bulk a �crit :


Why not using a duplex 120km and a circulator[1] ? This could be far
more reliable if you avoid PC connectors on the way.

You may also mux several DWDM waves using this and a low-loss mux (found
<1.5dB for 8 channels).

Of course, for such lenghts, you may need a chromatic dispersion

[1] http://www.thorlabs.de/newgrouppage9.cfm?objectgroup_id=373

You're the first person to suggest that kind of configuration, so thanks.

We ended up purchasing an 8-wave DWDM from our transport vendor, as it
solved the problem and gives us a path to future growth.