[Tfug] Cabling between buildings

[Choprboy]

On Wednesday 27 May 2009 23:50, Bexley Hall wrote:
>
> Aside from the bandwidth differences, I'm wondering why he
> can't use something *like* DSL.  I mean TPC runs cable
> miles from the CO to the subscriber and you don't see
> DSL modems getting fried by the dozens each time there's
> a lightning storm.  What's the difference between the
> CO side and subscriber end wrt DSL modems?  I.e., can you
> get two DSL modems to talk to each other like you could
> with an analog modem (assuming you provided BORSCHT)?
>


You can get two DSL modems back-to-back, but only a handful of modems ever 
supported it, one of the modems has to become the "CO" side providing sync. 
There was a really good article a number of years ago written by someone who 
got a dry line between to offices a couple miles apart and setup back-to-back 
modems to connect them, his experiences/problems, and suggestions for 
equipment.  I think it was back in Ohio... but searching all over I can;t 
find it. I seem to vaguely remember him using Netopia DSL modems, probably 
the reason I picked one up along the line somewhere.

Normally, for DSL, a DSLAM is used on the head end with multiple DSL modems 
out in the field. There was another great article years ago about a goup of 
residences, out in the woods, that could not get broadband. The local lines 
were terrible and barely supported modem speeds. They formed a coop and used 
the various CLEC/ILEC laws to force the local provider to provide a 
cross-connect cabinet in their subdivision. The coop then installed their own 
DSLAM next to the cabinet and a backhaul out to the internet on wireless... 
They essentially started their own ISP. I am pretty sure this is the coop:
http://www.rric.net/

Either way, you still need grounding on either end. Your in-place phone lines 
should already be grounded at the building entrance (the phone demarc). The 
DSLAM end must also be grounded, typically either a complete rackmount shelf 
as part of the voice/DSL splitter assembly or a series of 66 block mounted 
line surge arresters.


Adrian