12-2
Cisco Secure Router 520 Series Software Configuration Guide
OL-14210-01
Chapter 12 Troubleshooting
ADSL Troubleshooting
ADSL Troubleshooting
If you experience trouble with the ADSL connection, verify the following:
• The ADSL line is connected and is using pins 3 and 4. For more information on the ADSL
connection, see the hardware guide for your router.
• The ADSL CD LED is on. If it is not on, the router may not be connected to the DSL access
multiplexer (DSLAM). For more information on the ADSL LEDs, see the hardware installation
guide specific for your router.
• The correct Asynchronous Transfer Mode (ATM) virtual path identifier/virtual circuit identifier
(VPI/VCI) is being used.
• The DSLAM supports discrete multi-tone (DMT) Issue 2.
• The ADSL cable that you connect to the Cisco router must be 10BASE-T Category 5, unshielded
twisted-pair (UTP) cable. Using regular telephone cable can introduce line errors.
ATM Troubleshooting Commands
Use the following commands to troubleshoot your ATM interface.
• ping atm interface Command
• show interface Command
• show atm interface Command
• debug atm Commands

ping atm interface Command

Use the ping atm interface command to determine whether a particular PVC is in use. The PVC does
not need to be configured on the router to use this command. Example 12-1 shows the use of this
command to determine whether PVC 8/35 is in use.
Example 12-1 Determining If a PVC Is in Use
Router# ping atm interface atm 0 8 35 seg-loopback
Type escape sequence to abort.
Sending 5, 53-byte segment OAM echoes, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 148/148/148 ms
This command sends five OAM F5 loopback packets to the DSLAM (segment OAM packets). If the PVC
is configured at the DSLAM, the ping is successful.
To test whether the PVC is being used at the aggregator, enter the following command:
Router# ping atm interface atm 0 8 35 end-loopback
Type escape sequence to abort.
Sending 5, 53-byte end-to-end OAM echoes, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 400/401/404 ms