Fibre Channel Physical Layer
Media Types
If we run over 62.5 micron fibre, these are the maximum recommended
distances.
If we run over 50 micron fibre, you can see that the maximum recommended
distance is slightly increased.
Both types of multimode fibre use exactly the same transmitter, exactly the
same receiver, exactly the same connector – all we actually change is the
physical fibre.
What we are really interested in is the transmit and receive powers. The faster
we clock something the more power it takes so the faster we clock it the
shorter the distance becomes.
With single mode it is always 9 micron.
The original specification was to use a 1310 nanometre wavelength which
recommended a maximum distance of 10 kilometres.
Longwave transmitters offer a much purer transmit source.
By using a 1550 nanometre wavelength, theoretically you should be able to do
120km at all speeds.
The distances stated are the recommended maximum distances, assuming a
direct connection. If you use a patch panel you will get some loss so the
distance will lessen. If you try and mix fibre types the distance will lessen
considerably.