6
7 Connect an ISDN Line
Follow these steps to connect an ISDN U line to use the data service unit (DSU) features of the router.
Caution Always connect the red cable to the red ISDN U port on the router. Do not connect either cable to the yellow
Ethernet port. Accidently connecting these cables to the wrong port can damage your router.
Figure 3 Connecting a Cisco 811 or 813 Router to an ISDN U Line
Step 1 Connect the red cable with the RJ-11 connector to the red ISDN U port.
Step 2 Connect the other end of the cable to the ISDN wall jack with an RJ-11 connector.
Step 3 Verify that the DSU button is set to the ON position.
Step 4 Check the DSU LED on the front panel after router power-up. If the DSU LED is not on, try pressing the NOR/RVS
button.
Cisco 813 router
TO HUB
TO PC
Model Cisco 813
4
3
2
1
ETHERNET 10 BASE T PHONE
CONSOLE ISDN S/T ISDN U
ISDN U 2
1
+5, -24, -71 VDC
ISDN wall jack
ON
NOR
RVS
DSU
OFF