Outside plant - prewire customer demarc preference

Fri Nov 24 05:56:47 UTC 2023

On 11/22/23 12:35, Sean Donelan wrote:
>
> For *only* $1,000, the builder is willing to pre-install a smurf tube 
> from the demarc to the central distribution point.  But such a deal 
> for 5G....

Yeah that's ridiculous.  Running such a thing while the walls are still 
open is a piece of cake, and the material is maybe $50-100 depending on 
distance.

> Since most fiber installs seem to use pre-connectorized cable, without 
> affecting building structure integrity (i.e. 2-inch is too big 
> according to builder), how small is too small?  Trade size 1/2-inch, 
> 3/4-inch, 1-inch?
>
> Does the FTTH industry have any published standards?

At least my experience has been that, where pre-connectorized drop 
cables are used, they're only pre-termed on the telco side (often, but 
by no means always in a hardened connector).  The customer side is 
either unterminated or uses a small ferrule with a snap-on housing 
precisely so that it can be fished through small holes in walls/framing 
and small or crowded conduits.

In practice, 1/2" trade size smurf tube is big enough if it's not too 
long and bendy especially if they're willing to get one with a 
pull-string already in it (and the guy before you is nice enough to pull 
another).  If it's a long or bendy drop or you want a little extra piece 
of mind, 3/4" is readily available not too expensive.  1" starts to get 
a bit expensive and is usually unnecessary.

I personally connectorize both sides in the field.  Having the ability 
to do it is invaluable for repairs, and it's not that much harder to do 
two sides than one especially if you're already fishing wires and such.  
If you're using hardened connectors, the situation is different since 
they're not commonly available for field install, though it is a thing 
you can get.

I'm not aware of any published standards focusing on FTTx in North 
America.  All the standards I know of are datacenter/mid-size business 
oriented and are going to call for ridiculous (in FTTx) things like 2"+ 
rigid conduit on the assumption it'll have at least a 48F loose-tube in 
it and probably more than one.

I would imagine some of the national ogre telcos who are still doing 
FTTx deployments will have a pre-build guide for at least MDUs that 
might be useful, though around here they often just show up when the 
first person orders service and treat the building as "existing" even if 
it was just built last week.  I'm guessing they have so many existing 
buildings to deal with at least right now that this isn't a huge deal 
for them and may even be easier than having two classes of MDU installs 
(existing and pre-wire). AT&T and Centurylink/Lumen are the most likely 
to have them IMO, but checking Frontier/Verizon (do they still have ANY 
wireline territory?) may be useful, too, especially since they were the 
earliest ones to do it.

--
Brandon Martin