100G over 100 km of dark fiber

Sat Oct 31 21:03:26 UTC 2020

Hi Jared,

Easiest thing would be breaking into sub-100G channels (e.g. 4x 25G) and
using DWDM optics + Amp + Compensation + Pre-Amp to transport it across the
100km.

Same parts for all configs:
*) 1x Amplifier => 1 slot
*) 1x 100km dispersion compensation => separate 1U
*) 1x Pre-Amplifier => 1 slot

Sample config per site:

*) 1U chassis (4 slots)
*) 1x Mgmt card => 1 slot
*) [same parts for all configs]
*) 1x 25G converter (100G client port split into 4x 25G SFP28 line ports) =>
1 slot
*) 1x 8 channel DWDM Mux/Demux => separate 1U
*) 4x 25G SFP28 DWDM 10km
*) 1x 100G QSFP28 SR/LR (this is only for the client port on the converter -
you need a second one for your device)

=> footprint per site ~6200 USD for 1x 100G

The above setup requires 3U of rack space per site and provides 4 more DWDM
channels as spares for further upgrades and the DWDM unit will have an
separate upgrade port, to expand the number of filters (if you do not want
to replace the whole filter with a bigger one).

If you you want to go for a solution which starts with 4x 100G you're on the
13k USD range (per site):

*) 2U chassis (8 slots)
*) 1x Mgmt card => 1 slot
*) [same parts for all configs]
*) 4x 25G converter (100G client port split into 4x 25G SFP28 line ports) =>
4 slots
*) 1x 16 channel DWDM Mux/Demux => separate 1U
*) 16x 25G SFP28 DWDM 10km
*) 4x 100G QSFP28 SR/LR (this is only for the client port on the converter -
you need a second one for your device)

=> footprint per site ~13000 USD for 4x 100G

Even expansion to 12x 100G is more or less "cheap":

*) 5U chassis (16 slots)
*) 1x Mgmt card => 1 slot
*) [same parts for all configs]
*) 12x 25G converter (100G client port split into 4x 25G SFP28 line ports)
=> 12 slots
*) 1x 48 channel DWDM Mux/Demux => separate 1U
*) 48x 25G SFP28 DWDM 10km
*) 12x 100G QSFP28 SR/LR (this is only for the client port on the converter
- you need a second one for your device)

=> footprint per site ~31000 USD for 12x 100G

I typically go for Sintai, FS.com and Edgeoptics components. Regarding the
compensation and AMPs stuff: it's just math, nothing else :).

Best regards
Jürgen