Cisco Systems OL-27407-01 manual Connecting a Voice Isdn BRI Line

Chapter 3 Connecting the Router

Cisco 860, 880, 890 Series

This option allows a stepped offhook resistance during seizure, which avoids overloading the circuit during offhook in the event that ringing voltage is present on the circuit at the same time as the trunk seizure. The stepped offhook resistance is initially set to 800 Ohms, then adjusts to 50 Ohms when ringing voltage is not present.

To enable the soft-offhookcommand on the port, and to access the connection command with plar opx syntax, see the Cisco Command Lookup Tool.

Connecting a Voice ISDN BRI Line

Use a straight-through RJ-45 cable to connect the voice BRI port to the ISDN network through a telephone outlet or other device.

Caution To prevent damage to the router, be sure to connect the BRI cable to the BRI connector only and not to any other RJ-45 connector.

To connect the voice BRI line, follow these steps:

Step 1 Connect one end of a straight-through RJ-45–to–RJ-45 cable to the Voice BRI port.

Note When the interface is configured as NT and is connecting to a TE device, use a crossover cable. See Table A-27.

	Cisco Integrated Services Router Hardware Installation Guide
3-42	OL-23125-02