How to calculate distance between 2 networks

[proy1_10]

Hi!,
I'm working in a project where we need to give support to a optical fiber client and I need to know distances between nearest center to every network (network of my company and client network).

Do you think of any quick and easy way to do it?

Thanks in advance
BR

[BENDISA]

hi

we use an OTDR to mesure attenuation /Km =(0.25db/km) for 1550nm,then finaly in report the OTDR give a distance (km )