T1 short-haul vs. long-haul

Thu Jul 22 09:35:17 UTC 2004

Michel Py wrote:
>>The installer should test from the extended
>>demarc (make sure they do).
> 
> The installer and all the techs always test from the demarc, whether or
> not it's extended. What you DON'T want to do is to extend the demarc
> yourself (because you don't actually extend it), and here's why:

Ok, now I've got some more questions regarding demarc and placement of the
various units:

o What is the "demarc"?  Is it the jack/punch-block where the SmartJack is
   connected to?
o What is an "MPOE"?
o What is the "NIU"?
o Where is the SmartJack normally located?  In your offices or somewhere else
   in the building (maybe some room where the cable to the CO is terminated)?

Lets me shortly explain how this works around here (Europe/CH).  Every building
has a cable to the CO which terminates into some kind of box or room unsually on
the ground floor onto either solder-strips or punch-blocks.  From there on it's
building cabling and the responseablility of the customer and/or building owner.
For an POTS connection the demarc is clearly at that point.  When something is
wrong they will go there and only the and test it.  If the fault is your in-house
cabling you have to pay the techie.  However with data services (E1) it's a bit
different.  The in-house cabling from the box to your office or router location
is your business but the SmartJack (the HDSL2 thingy) is being installed next to
the router or whereever you chose to run the cable.  When the Telco techie comes
to install and test the SmartJack (which is the demarcation point for the data
service) he expects the in-house cabling to be done and working fine.  If not,
and it's your fault, you pay.  Ok, after all this works and the 15 minutes BERT
from the E1 side of the SmartJack is successfully completed the Techie leaves
and is happy.  Now if something goes wrong there are a number of possibilities.
The HSDL connection between the SmartJack and CO can be lost and in this case
you and they will notice because you get an alarm on both sides.  Normally the
the SmartJack has an LED for uplink status.  Easy to figure out but then?  First
you have to check out your in-house cabling whether it's still working.  If not,
have it fixed.  If it's fine, then call Telco to have their side fixed.  It does
indeed happen that they manage to break the patch within their CO or somewhere
in the street cabinet.  When the HDSL uplink of the SmartJack is working then
it's the sole problem of the Telco.  Probably they managed to disconnect the
line somewhere on the SONET/SDH side or in some MUX.

          street               building                E1
CO -----------------> box ---------------> SmartJack ----> Router
                        |                        |
                   Cable demarc           Service demarc
      Telco resp. ----->|<------ your resp. ---------------------->

-- 
Andre