Channelized E1 Connections - Cisco EF4116 Hardware Installation And Maintenance Manual

Network Connection Considerations

Channelized E1 Connections

The Cisco 4000 series router supports a channelized E1 (CE1) network processor module with one
E1 interface.The CE1 provides one channelized E1 connection via a serial cable to a channel service
unit (CSU). On the CE1, the controller provides up to 24 virtual channels. Each virtual channel is
presented to the system as a serial interface that can be configured individually. This interface is the
physical media that supports ISDN PRI.
The CE1, shown in Figure 2-34, provides a controller for transmitting and receiving data
bidirectionally at the E1 rate of 2.048 Mbps. For wide-area networking, the CE1 can function as a
concentrator for a remote site.
Figure 2-34
Following are the E1 specifications:
•
•
•
•
CE1 Jumper Settings
The jumpers on the CE1 module set capacitive coupling between the transmit or receive shield and
chassis ground, and the cable resistance (120-ohm or 75-ohm).
By default, the CE1 module is set with capacitive coupling between the receive (Rx) shield and
chassis ground. This provides direct current (DC) isolation between the chassis and external devices,
as stated in the G.703 specification. Jumper J2 (see Figure 2-35) controls this function. To set
capacitive coupling between the transmit (Tx) shield and chassis ground, set jumper J2 as described
in Table 2-7.
Figure 2-35 also shows the location of jumpers J1, J3, J4, J5, and J7. These jumpers set the cable
impedance to 120-ohm or 75-ohm. The figure shows the cable impedance set to 120-ohm.
2-32 Cisco 4000 Series Hardware Installation and Maintenance
Channelized E1 Network Interface Processor
DB-15
female
Transmission bit rate: 2.048 Mbps
Output port specifications: see G.703 / Section 6.3 (CCITT specification)
Input port specifications: see G.703 / Section 6.3 (CCITT specification)
Jitter attenuation starting at 6 hertz (Hz), which meets or exceeds G.823 for E1
cE1 / PRI
50 ppm