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. http://arneill-py.sacramento.ca.us/photos/smartjack1_lr.jpg 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. http://arneill-py.sacramento.ca.us/photos/smartjack2_lr.jpg A little more detailed. As you can see, there is nothing smart about these, it's a glorified patch panel. http://arneill-py.sacramento.ca.us/photos/smartjack3_lr.jpg
From a distance. The white punch blocks are called "66 blocks".
http://arneill-py.sacramento.ca.us/photos/smartjack4_lr.jpg Sometimes the LEC does not install a smartjack, leaving the customer and/or contractor to punch it, which typically produces a smartjack like this :-) http://arneill-py.sacramento.ca.us/photos/niu1_lr.jpg 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. http://arneill-py.sacramento.ca.us/photos/niu2_lr.jpg Another variation of NIU, very common too. Both NIUs receive power from the telco. Here are the hires: http://arneill-py.sacramento.ca.us/photos/smartjack1_hr.jpg http://arneill-py.sacramento.ca.us/photos/smartjack2_hr.jpg http://arneill-py.sacramento.ca.us/photos/smartjack3_hr.jpg http://arneill-py.sacramento.ca.us/photos/smartjack4_hr.jpg http://arneill-py.sacramento.ca.us/photos/niu1_hr.jpg http://arneill-py.sacramento.ca.us/photos/niu2_hr.jpg If I have time tomorrow I will post some pictures of an extended DS-3 demarc at a remote site. Michel.