Standard terminology for a dark fiber path?

What is the standard terminology for strands of dark fiber spliced together
to form a continuous path between points A and Z?

I have seen:

   - *fiber circuit* [but also seen used to denote a connection at the
   network layer over a physical fiber connection. This definition of circuit
   would include the dark fiber path, the transmitters and receivers and logic
   making up the data and network layers.]
   - *fiber loop *[ Does a loop define an electrical circuit with two
   physically separate positive and negative strands? In that case, is this a
   Bellhead remnant? ]

I am particularly interested in last mile systems, but I don't see any
reason that the term wouldn't be the same in the middle mile.


What do you call it if it is made out of copper instead of glass? Or air?

I don't see anything wrong with "fiber path".

(Answering my own question, maybe: "dry pair from A to B". "[Microwave] Radio link between A and B.")

Just my .02 but I would think to call it a "single fiber link" or perhaps
just a "fiber link". A fiber path doesn't strike me as being one solid
connection but could instead include patching in the middle and not be a
continuous strand. As far as fiber loop, that is used to reference the
OC192 transport ring that exists in the DC metro area. Again, this is just
come to accept that I need to always ask qualifying questions to determine
what they truly mean.


Anthony R Junk
Network and Security Engineer
(410) 929-1838

IDK what elsewhere uses but strand or (less common) span is the common
term I've seen specifically for a passive piece of glass between two

FWIW, at my $dayjob (a fiber-based service provider), the accepted term is
"span", which accounts for any continuous segment between add/drop and/or
regen locations (i.e. no provider or end user electronics in the middle,
only at the endpoints). The most common alternate I come across is

Re a couple of earlier suggestions - A patch between cables to provide
continuity, as compared to a fusion splice, doesn't inherently change this
view, as it has no bearing on the logical use of the span. Similarly,
"strand" isn't favored as it assumes a single fiber only, where the vast
majority of applications require a pair (or multiple pairs), so doesn't
accurately reflect the logical use of the span. I think "1F Span" is the
favored reference for a single-fiber deployment, for the sake of both
consistency and clarity.

+1 on span along with fiber count designation.

As Dave C pointed out, it commonly referenced as a Fiber Span. The fiber
span would be inclusive of any splice points and/or patches needed to
provide connectivity between point A and point Z.

A Fiber Stand is a single piece of glass within the cable sheath, often
spliced to create a fiber span.

A Dark Fiber Circuit commonly refers to the service/product that was sold
by or bought from a Service Provider. The Dark Fiber Circuits are turned
over to the customer as a fiber span between point A and point Z.

It should also be noted that the span can consist of 1 fiber or a pair of
fiber. It is common for service providers to us "Bi-Di" optics, allowing
the use of 1 fiber for transmit and receive between their equipment.