B-4
Cisco MWR 1941-DC-A Mobile Wireless Edge Router Hardware Installation Guide
OL-7872-04
Appendix B Cable Specifications
Fast Ethernet Connector Pinouts
To identify a rollover cable compare the modular plugs at the two ends of the cable. When you hold the
plugs side by side, with the tab at the back, the wire connected to the pin on the outside of the left plug
should be the same color as the wire connected to the pin on the outside of the right plug (see
Figure B-2
.) If you purchased your cable from Cisco Systems, pin 1 is white on one connector, and pin
8 is white on the other (a rollover cable connects pins 1 and 8, 2 and 7, 3 and 6, and 4 and 5).
Figure B-2
Identifying a Rollover Cable
Fast Ethernet Connector Pinouts
This section illustrates the Fast Ethernet 100Base-TX (RJ-45) connector and lists its pinout and signal
descriptions.
Figure B-3
shows the 100Base-TX RJ-45 connector, and
Table B-4 on page B-5
lists its pinouts. The
1-port Fast Ethernet network module RJ-45 port actively terminates wire pair 4 and 5 and wire pair 7
and 8. Common-mode termination reduces electromagnetic interference (EMI) and susceptibility to
common-mode sources.
Figure B-3
100Base-TX RJ-45 Connector
Pin 1
Pin 8
H3824
Pin 1 and pin 8
should be the
same color
H1567
in 8
RJ-45 (both ends)
