Selecting a Serial Cable A-5
Serial Connection Example
Serial Connection Example
Figure A-1 shows a typical serial connection for the Cisco 805 router. In this example, the
router, which is a DTE device, is connected to a CSU/DSU or modem, which are DCE
devices.
Figure A-1 Serial Connection Example
The CSU/DSU or modem and its serial connector have the following characteristics:
•DCE device
•V.3 5
•Female
Because the serial devices are DCE, you should use a DTE cable to connect the router and
the CSU/DSU or modem. (For more information on the cable type needed to connect a
serial device, refer to TableA-2.)
Given these characteristics, the appropriate serial cable to connect the router and the
CSU/DSU or modem is a DTE V.35 male cable.
Note Some CSU/DSUs have a proprietary serial connector that will not mate with a Cisco
serial cable. If this situation occurs, you must provide an adapter (pigtail) cable that makes
the proprietary serial connector compatible with the Cisco serial connector. The gender of
the adapter cable should match the gender of the proprietary serial connector.
Cisco 805
router
DTE
device
DCE device
(provides clocking)
CSU/DSU
or modem
V.35 DTE cable
18958