Nortel Networks 8000 - Manual (Page 436)

10 Low-speed ATM configuration
Nortel Secure Router 8000 Series
Configuration -WAN Access
10.13.4 Pinging the peer fails though PVC is UP
Fault description
The PVC is UP, but after configuring the IPoA application, the peer cannot ping through.
Fault analysis
The possible causes are:
• The application modes configured at both ends are different.
• The protocol types encapsulated at both ends are different.
• The values of VPI/VCI configured on the both ends are not consistent.
Troubleshooting procedure
Do as follows on the routers:
Step 1 Check whether the peer supports the configured application mode. For example, if the local
terminal uses the PPPoA application, the peer should also support the PPPoA application.
Step 2 If the peer supports the configured application mode, check whether the AAL5 encapsulation
protocol types of the two terminals are the same. For example, they are mutually unreachable
with ping command if one terminal uses SNAP, and the other uses MUX. For certain clues,
enable the debugging of ATM packets.
Step 3 Check whether the local VPI/VCI and the peer VPI/VCI are consistent by using the display
atm pvc-info command. If not, use the pvc command in the ATM interface view to make
them consistent.
—End
10.13.5 Severe packet dropping and CRC errors occur though the
ping succeeds
Fault description
Two routers are directly connected and they are reachable with the ping command. Sometimes,
there is severe packet dropping and CRC check errors occur. Otherwise, the interface status
constantly changes to Up and Down.
Fault analysis
The possible cause is that the ATM interfaces at the two ends are not the same: one is
multimode fiber interface and the other is single mode fiber interface.
Troubleshooting procedure
Do as follows on the routers:
Step 1 Check the discarded packets and CRC check errors by using the display interface atm
command.
10-50 Nortel Networks Inc. Issue 5.3 (30 March 2009)