Establishing Connections to an NTU

The Network Termination Unit (NTU) is usually the first piece of equipment on the customer premise that connects to the ISDN line. Customer equipment must be cabled to the NTU. Dialogic does not supply a board to NTU cable. You must either purchase one from your supplier or build one yourself. If you are building your own cable, it must fit the following specifications:

Characteristic	Recommendations/Requirements
Cable Type:	The recommended cable type is twisted-pair cable in which each of the two pairs is shielded and the two pairs have a common shield as well. Shielding helps prevent noise and the twisting helps prevent cross talk.
Connectors:	The cable connects to the board via an ISO8877 Modular connector on the front or rear bracket of the board. See your NTU documentation for more information.

When building your NTU-to-board cable, be sure you understand how the NTU documentation has labeled NTU pinouts for transmit and receive to local equipment.

Be sure to test your cable after you have built and installed it. The green LEDs on the rear of the Digital Network Interface board turn on when the board firmware has been downloaded and the board is receiving clocking and synchronization information from the network.

NOTE:

If the pinout appears correct but you receive a red and green light, the transmit and receive may have to be switched on one end.

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