Cisco Systems CISCO1841-HSEC/K9-RF manual ISDN BRI Connections, CSU/DSU Connections

Chapter 5 Cable Information and Specifications for Cisco 1800 Series Routers (Modular)

Preparing to Connect to a Network

ISDN BRI Connections

The BRI WICs provide ISDN and BRI connections. BRI WICs are available with either an S/T interface that requires an external Network Termination 1 (NT1), or a U interface that has a built-in NT1. You can install the BRI WICs in any available WIC slots in the chassis.

Warning The ISDN connection is regarded as a source of voltage that should be inaccessible to user contact. Do not attempt to tamper with or open any public telephone operator (PTO)-provided equipment or connection hardware. Any hardwired connection (other than by a nonremovable, connect-one-time-only plug) must be made only by PTO staff or suitably trained engineers. Statement 23

Warning Hazardous network voltages are present in WAN ports regardless of whether power to the unit is OFF or ON. To avoid electric shock, use caution when working near WAN ports. When detaching cables, detach the end away from the unit first. Statement 1026

Use a BRI cable (not included) to connect the BRI WIC directly to an ISDN. Table 5-3lists the specifications for ISDN BRI cables. For information about pinouts, see Cisco Modular Access Router Cable Specifications.

Table 5-3	ISDN BRI Cable Specifications
Specification		High-Capacitance Cable	Low-Capacitance Cable
Resistance (at 96 kHz)		160 ohms/km	160 ohms/km
Capacitance (at 1 kHz)		120 nF1/km	30 nF/km
Impedance (at 96 kHz)		75 ohms	150 ohms
Wire diameter		0.024 in. (0.6 mm)	0.024 in. (0.6 mm)
Distance limitation		32.8 ft (10 m)	32.8 ft (10 m)

1. nF = nanofarad.

For more information on BRI WICs, see Installing Cisco Interface Cards in Cisco Access Routers.

CSU/DSU Connections

CSU/DSU WICs are available that provide switched 56-kbps connections, or full or fractionalized T1 connections.

For more information on CSU/DSU WICs, see Installing Cisco Interface Cards in Cisco Access Routers.

Cisco 1800 Series Routers (Modular) Hardware Installation Guide

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