Lights on a T1 Smart Jack

Shows what the lights on a T-1 smart jack (demark) should look like during normal operation. Also, shows what the lights will do when the circuit is broken.
There are 6 LED's on the Adtran smart jack in this video. In normal operation the top two are green and LED #4 & 5 should be yellow (or green).
If you see any colored light in the "Alarm" LED (3rd LED from top), that's not good
The T-1 Smart Jack is the phone company's equipment. It is also known a s the "Demark" or "Demac". This is the point at which the phone company is delineating their wiring infrastructure is ending and yours is beginning.
Many people mistakenly think the smart jack is some type of necessary converter. The reality is, the T-1 will function just fine even if you were to wire around the smart jack. The smart jack functions as a diagnostic tool for the phone company. The can use it for testing by communicating with the smart jack to do things such as LoopBack.
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[@nicosohos2933]

The equipment shown in the tutorial is an Adtran HDSL Transceiver Unit - Remote unit, AKA: HTU-R. The HTU-R works in tandem with a a HTU - C (Central) unit that cane be located in the Central Office, Controlled Environmental Vault (CEV) or at a optical multiplexer closest to the customer location via either two or four metallic wires. HDSL systems can be deployed as two or four wire DSL systems. Depending on how far the customer is located from the C Unit. Two wire HDSL systems did not deploy with doubler (Repeater) units because of Telcordia/Bellcore Standards, as compared to four wire HDSL equipment that do support HDSL span doublers.
The typical T1 PM-NIU AKA T1 Smart Jacks deployed after 2000 are capable of storing on board performance statistics (PM) in real time, and in stored memory. The T1 PM-NIU's deployed by Verizon typically have been found to have the most enhancements in the industry by design. I know this to be true since I was the lead transmission engineer at Bell Atlantic, latter Verizon that specified the performance monitoring parameters of the T1 PM-NIU's, and next generation HDSL equipment.
To access the T1 PM registers on the T1 NIU or HDSL Remote unit, all that is required is to connect a serial port of a PC or any dumb terminal with VT-100 emulation with a nine pin straight serial cable @ 9600 8 its no parity. Tap the space bar of the PC/Terminal and the equipment will Auto-Baud and display a welcome screen.
By examining the PM registers of the T1 NIU or HTU-R, the site technician can obtain information relative to the health of the DS1 signal, and to the HDSL line if accessing a HTU-R device.

[@simbadurio444]

nice explanation

[@ShawnaTW]

Thanks! This really helped me out.

[@NetworkAdvisor]

So Glad Shawn. Thanks for the feedback. I don’t get many comments on that video. 😊

[@tonyzeno2715]

What does it mean when the DS1 light is Steadt Green but every 10 to 20 secs it will blink Red??