[c-nsp] Cable runs

[Bill Wichers]

> How long can you run coax for a DS3 before you start running into
> problems?  We are kicking around the idea of moving our Networking and
> server gear to a new location within the same building but leaving the
> telco gear in the MDF.  I'm thinking the cable run would be about 100 to
> 150 feet.  Will we run into problems?

Depends on the kind of coax you use.

734 (approx 1/4" diameter) allows up to 450 feet
720 (approx 1/8" diameter) allows up to 255 feet
735 (approx 1/8" diameter) allows up to 230 feet

734 is roughly the equivalent of RG59 w/ BC (Bare Copper) center
conductor, although RG59 is *not* the correct cable type for DS3.

Absolute theoretical max distance is about 900 feet on 734 cabling, at
which point the waveshape starts to degrade enough that most equipment
will have a hard time extracting useable data from the signal. I did
extend a DS3 to about this distance once for a customer and it did work
when LBO was set to max on both ends, but I wouldn't recommend it.

For your 150 foot application, just use 735 cable, preferably the paired
stuff if you only have one circuit. 735 is a lot easier to work with than
the larger 734 cable, and it's cheaper too. You should consider using
73506 (Commscope part number) or one of the other multi-count cables if
you have more than one DS3 circuit. Make sure whatever you use has an
exterior jacket to protect it during installation (the non-jacketed stuff
is really only good for patch cords), and use plenum if you run it in a
plenum (air handling) space.

     -Bill


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Waveform Technology
UNIX Systems Administrator