Installation guide

4-84 Cisco 4000 Series Installation Guide
Network Connection Considerations
Warning Network hazardous voltages are accessible in the BRI cable. If you detach the
BRI cable, detach the end away from the router first to avoid possible electric shock.
Network hazardous voltages are also accessible on the BRI module in the area of the BRI
port (RJ-45 connector), even when power is turned OFF. (To see translated versions of this
warning, refer to the appendix “Translated Safety Warnings.”)
The specifications for the BRI cable are given in Table 4-8.
Table 4-8 BRI Cable Specifications
Note The multiport BRI network processor module requires that all its interfaces connect
to the same carrier or from carriers with synchronized master clocks. If the BRI module
connects to ISDN interfaces which have an unsynchronized master clock, the module’s
interfaces will occasionally lose some packets.
Channelized T1/ISDN PRI Connections
The Cisco 4000 series routers support a channelized T1/ISDN PRI (CT1/PRI) network
processor module with one T1 interface.The CT1/PRI module provides one channelized T1
connection via a serial cable to a channel service unit (CSU). On the CT1/PRI module, the
1. kHz = kilohertz.
2. nF = nanoFarad.
Parameter High-Capacitance Cable Low-Capacitance Cable
Resistance (@ 96 kHz
1
) 160 ohms/km 160 ohms/km
Capacitance (@ 1 kHz) 120 nF/km
2
30 nF/km
Impedance (@ 96 kHz) 75 ohms 150 ohms
Wire diameter 0.024" (0.6 mm) 0.024" (0.6 mm)
Distance limitation 32.8' (10 m) 32.8' (10 m)