Nortel ISDN Signaling Link, Description, Installation And Operation

Page: 349 / 380

Appendix A: Cable description and NT8D81BA cable replacement Page 349 of 378
ITG Trunk 2.0 ISDN Signaling Link (ISL) Description, Installation and Operation
Prevent ground loops on connection to external
customer LAN equipment
The shielded RJ45 coupler is the connection point for the customer’s shielded
Category 5 LAN cable to the hub, switch, or router supporting the T-LAN and
E-LAN. You must use shielded Category 5 RJ45 cable to connect to the
customer’s T-LAN/E-LAN equipment.
1 Connect the customer-provided shielded Category 5 LAN cable to the
external LAN equipment. Ensure that the external LAN equipment is
powered-up.
2 Use an ohmmeter to measure resistance to ground between the free
end of the shielded RJ45 cable and building ground.
The ohmmeter must measure Open to ground before plugging it into
the shielded RJ45 coupler on the end of the NTMF94DA.
If it does not measure Open, you must install the unshielded RJ45
coupler (provided) on the end of the NTMF94DA to prevent ground
loops to external LAN equipment.