Troubleshooting guide

Layer 1 Issues
Is the carrier detect (CD) light on the front panel of the Cisco DSL Router
on or off?
If the CD light is on, go to the Layer 2 Issues section of this document.
If the CD light is off, continue with the next question.
Is your ISP using a DSLAM that supports the Alcatel chipset?
Verify this information with your ISP.
Is the DSL port on the back of the Cisco DSL Router plugged into the
DSL wall jack?
If the DSL port is not plugged into the DSL wall jack, connect the port to the wall with a 4−pin or 6−pin
RJ−11 cable. This is a standard telephone cable.
Is the ATM interface in an administratively down state?
To determine if the ATM0 interface is administratively down, issue the following command in enable mode
on the router:
Router#show interface atm 0
ATM0 is administratively down, line protocol is down
<... snipped ...>
If the ATM0 interface status is administratively down, issue the no shutdown command under the ATM0
interface.
Router#config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#interface atm 0
Router(config−if)#no shut
Router(config−if)#end
Router#write memory
Is the cable pinout correct?
If the ATM0 interface status is down and down, the router is not seeing a carrier on the ADSL line. This
generally indicates one of two issues:
The active pins on the DSL wall jack are incorrect.1.
Your ISP has not turned up an ADSL service on this wall jack.2.
Cisco DSL Router xDSL Port Pinouts
The RJ−11 connector provides an xDSL connection to external media via a standard RJ−11 6−pin modular
jack.
Cisco DSL Router Configuration and Troubleshooting Guide