Installation guide

Making External Connections to Cisco 4000 Series Routers 4-89

Network Connection Considerations

Table 4-9 Jumper Settings and Functions

Warning

To prevent problems with the E1 interface and to reduce the potential for injury,

jumper J2 should be conﬁgured by trained service personnel only. For either impedance

option, a jumper installed at J2 bypasses the alternating current (AC)-decoupling capacitor

to ground, thereby coupling the interface directly to AC. This is a setting that could pose a

risk of severe injury. By default and for safety, J2 has been conﬁgured with no ground. (To

see translated versions of this warning, refer to the appendix “Translated Safety

Warnings.”)

E1 Cabling

Four serial cables are available from Cisco Systems for the CE1/PRI network processor

module. All four cables have DB-15 connectors on the router end and either BNC, DB-15,

Twinax, or RJ-45 connectors on the network end. Figure 4-45, Figure 4-46, Figure 4-47,

and Figure 4-48 show the E1 interface cables.

Figure 4-45 E1 Interface Cable for 75-Ohm, Unbalanced Connections

(with BNC Connectors)

1. All jumpers must be set to the same impedance.

Jumper Position Function

J2 1 and 2

2 and 3

Connects the RX shield to chassis ground.

Connects the RX shield through capacitive coupling to chassis

ground.

J1, J3, J4,

J5, J7

1 and 2

2 and 3

Sets cable impedance to 120 ohms.

Sets cable impedance to 75 ohms.

H2421