It is absolutely true that the cost of installing fiber to the
desktop is quite similar to that of copper. Where you really
run into cost with a fiber plant is the cost of the electronics
(NIC cards, fiber converters, fiber interfaces in switches,
fiber interfaces for you plain old telephone, etc). Previous
writers have pointed this out quite clearly and I don't think
anyone with any experience in this area will argue about that
issue. It is foolhardy to install a fiber-only cable plant.
The question really should be turned around to be: what type of
wiring should be placed to the desktop to support various networking
technologies and speeds.
A quick synopsis:
100baseTX (100Mbs) -- supported on cat5 cable plant
1000baseTX (Gigabit Ethernet) -- supported on a cat5e cable plant
10Gbase (10 Gig Ethernet) -- here are where the questions start.
10 gig is an ongoing effort, so there are really no answers
yet, just a lot of speculation. Some comments on media
singlemode fiber - a number of 10G standards support
singlemode fiber. Interfaces are expensive and will
multimode fiber - 50 micron is no problem for 100 meters
62.5 micron is trouble unless you use one of the
interfaces that does course wave division multiplexing
again, the optical interfaces are expensive.
category 7 - this looks like a sure bet -- 10GbaseT should
support 100 meters of cat7 cable.
category 6 - the 10GbaseT standards work looks like it
will support category 6 cabling, probably for a limited
distance (maybe 55 meters).
category 5e - there is a huge push in 10GbaseT standards
committee to support it -- probably for a limited
distance (20 to 50 meters).
four coax - There is a standard that supports 15 meters
of a four coax cable system (10GbaseCX4). This was
targeted for data center applications, but seems like
a sure looser due to the ongoing work on 10GbaseT
There remains a *huge* amount of uncertainty around cat6 and
cat5e with the work in the 10GbaseT standards groups. A few
So, if you want your structured cable plant to support gigabit
Ethernet, then install category 5e cabling. If you want to
try to support 10 gig, you are in a quandary. Should you do cat7
or can you get by with cat6 or maybe even cat5e. Hmmmm.......
Our current thinking is that gigabit is sufficient for most
desktop and other applications, so we're doing extra headroom
cat5e to most outlets and cat5e + fiber (both SM and MM) to server
Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/cg/.