RE: T1 short-haul vs. long-haul

SmartJack with demarcation point in the office (or
same floor) instead of the building entrance point

I can't emphasize enough the importance of this, read ahead.

Mark Kent wrote:
You are not likely going to be able to control that,
it depends on how the install tech's day is going.
Strictly speaking, I believe they are supposed to put
it at the MPOE.

For the smart jack, it depends on the telco and/or if the telco also is
the CLEC.

You buy the T1 from AT&T, and they use SBC (formerly Pacific Bell) as
the CLEC. The only way you will get the demarc extended in your premises
is to have the router managed by AT&T, and then the demarc is the
Ethernet port of their router. If you have your own router the demarc is
the smart jack, the smart jack is at the MPOE and anything between the
smart jack and you is your responsibility, which is terrible as I will
explain below.

Example2: You buy the circuit from XO and they are their own CLEC. As
you hold the sales droid by the cojones you will be able to have the
demarc extended to your premises.

As you order the circuit specify where you want it to
end up ("server room, 2nd floor") and that you want an
extended demarc (will cost extra).

Yes, yes, yes. It is worth the extra cost.

AT install time, make sure someone is around to cajole the
installer into getting the NIU as close as you can to where
your router will be.

This is where there isn't much you can do about. I have tried several
times to "cajole" with 200 bucks in cash and/or other incentives; it did
not happen.

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:

- Let's assume example 1 above.
- The demarc is at the MPOE; the smart jack is 1ft away from the NIU;
you have a 300ft cat5 cable between the smart jack and the CSU/DSU in
your premises.
- You drop packets; you have 65 identically configured sites, you
replaced the router and the CSU/DSU twice already, and you still drop
packets. As the config can't be at fault as it works fine on the other
64 sites and the hardware can't be at fault since you replaced every
piece of it including the power cord and the patch cords twice, it's
obviously a circuit issue, right?
- You call AT&T. "It works on my side" (remember this sentence).
- You call SBC. "It works on my side". That is, if you get them to talk
to you as the circuit goes to AT&T and they will likely say "talk to
- You call AT&T again. "It works on my side".
- You call your AT&T sales droid and threaten not to pay the bill and
sue them.
- After 2 days of ping-pong you finally get an SBC tech to come and test
the line (possibly by lying at the number of CRC errors).
- The SBC tech comes, plugs the pattern tester at the smart jack, loops
the remote CSU/DSU, and it all tests clean.
- The SBC tech report that the circuit is clean, now you're back dealing
with AT&T.
- More time passes by. You finally get the AT&T tech to come. He does
the same as the SBC tech: plugs the tester at the demarc and runs bit
patterns. "It works on my side".
- You say: but I need it to work at my router, not in the MPOE room.

Tough luck, buddy. Our responsibility stops at the demarc; it tests
clean, we don't give a rip if you extended the demarc to your office.

Tough luck. Sometimes pattern testers detect line issues, sometimes they
don't. Now you have to move your CSU/DSU and router in the MPOE room
(possibly open to all winds) and _prove_ them that it's a circuit issue.
Morale: you want the demarc extended to the same room you have the
CSU/DSU in your premises, ESPECIALLY if there is more than one company

Get a standard built-in T1 dsu like as been mentioned in
previous posts. Plug it into the extended demarc with an
ethernet patch cable.

Yes indeed. CAT5 is your friend even if it's not necessary on paper.


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. ---------------------->