RE: T1 short-haul vs. long-haul

Christopher Woodfield wrote:
In the interest of complicating things further, I think
you have NIU and smartjack backwards in your explanation

You think, which is a good beginning. Seeing it with your own eyes might
be of some interest, NTM that doing it for a living for 20+ years may
give new an entire new outlook on it.

For the entertainment of non-american readers, wannabes, and rookies I
stopped by a T1 MPOE on my way home and took a few photos.
These are smartjacks, RJ48. Two are connected (grey cable, on the right,
going directly to the CSU/DSU). The red/violet pairs on the right come
from the NIU.
A little more detailed. As you can see, there is nothing smart about
these, it's a glorified patch panel.

From a distance. The white punch blocks are called "66 blocks".
Sometimes the LEC does not install a smartjack, leaving the customer
and/or contractor to punch it, which typically produces a smartjack like
this :slight_smile:
A very common NIU with the Adtran modules. Each board is basically an
HDSL "modem", has lights and can be looped. Also present an RS-232 port
for configuring it with a laptop and the drop banana jacks to plug your
BERT tester.
Another variation of NIU, very common too. Both NIUs receive power from
the telco.

Here are the hires:

If I have time tomorrow I will post some pictures of an extended DS-3
demarc at a remote site.


hate to say it but what is pictured is not a smart jack, it is as you say a glorified patch.

a *TRUE* smart jack DOES have the tiny bit of circuitry necess'y to cause it to loop the line back when nothing is connected to it, some can do it via line signaling as well.

in some telco territory what they call a smart jack is, most certainly, NOT.

as always, YMMV, SBC/PacBell in SFO area usually does use a true smart jack, but not always. out of a number of t-1s installed for both voice and data while working at 2 Connecticut i was about 80/20 in favor of smart jacks.

I think we can probably chalk this up to a difference in dialect, for lack of a better word...what you're calling an NIU is exactly what I would call a smartjack and vice versa. Can you point to any sort of "official" documentation that defines these? I'm looking to see if anyone in my office has a Newton's as I speak...