Installation guide

4-86 Cisco 4000 Series Installation Guide
Network Connection Considerations
T1 Cabling
For the CT1/PRI network processor module, two standard T1 serial cables are available
from Cisco Systems: null-modem and straight-through. A straight-through cable connects
your router to an external CSU. Null-modem cables are used for back-to-back operation
and testing.
The cables have male 15-pin DB connectors at each end to connect the CT1/PRI module to
the external CSU.
The T1 interface cable has two 15-pin DB connectors at each end to connect the CT1/PRI
module to the external T1 CSU. Figure 4-42 shows the T1 interface cable, connectors and
pinouts.
Figure 4-42 T1 Interface Cable
Channelized E1/ISDN PRI Connections
The Cisco 4000 series routers support a channelized E1/ISDN PRI (CE1/PRI) network
processor module with one E1 interface.The CE1/PRI network processor module provides
one channelized E1 connection using a serial cable to a CSU. On the CE1/PRI module, 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.
Pin 1
Pin 9
Pin 11
Pin 3
Pin 1
Pin 9
Pin 11
Pin 3
72-XXXX-01 MIP
T1 or null-modem
connector (typical)
H2385