nanog mailing list archives

RE: 80 km BiDi XFPs


From: "Frank Bulk" <frnkblk () iname com>
Date: Sat, 6 Apr 2013 13:50:34 -0500

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

Frank

-----Original Message-----
From: Thomas Weible - FLEXOPTIX [mailto:Thomas.Weible () flexoptix net] 
Sent: Saturday, April 06, 2013 5:51 AM
To: Matt Addison; Frank Bulk
Cc: nanog () nanog org
Subject: AW: 80 km BiDi XFPs

Matt Addison [mailto:matt.addison () lists evilgeni us] wrote:

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.

Thomas
On Apr 2, 2013, at 19:16, Frank Bulk <frnkblk () iname com> wrote:

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.

Frank









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