Packets Fail to Be Forwarded on a G.SHDSL Interface Working in ATM Mode
This section provides a troubleshooting flowchart and a step-by-step troubleshooting procedure to use when packets fail to be forwarded on a G.SHDSL interface working in ATM mode.
1.Common Causes
This fault is commonly caused by one of the following:
l The cable is not properly connected to the interface or the interface is shut down.
l The local and remote G.SHDSL interfaces are using different transmission standards.
l The local and remote G.SHDSL interfaces are working in different PSD modes.
2.Troubleshooting Flowchart
Figure 1-1 shows the troubleshooting flowchart.
Figure 1-1 Troubleshooting flowchart for the packet forwarding failure on a G.SHDSL interface working in ATM mode
3.Troubleshooting Procedure
Procedure
Step 1 Check that the physical status of the G.SHDSL interface is Up.
Run the display interface atm command in the system view to check whether the physical status of the G.SHDSL interface is Up. The following information uses the display on ATM1/0/0 as an example.
l If "Atm1/0/0 current state : Administratively DOWN" is displayed, ATM1/0/0 has been shut down. Run the undo shutdown command on ATM1/0/0 to enable it.
l If "Atm1/0/0 current state : DOWN" is displayed, check the following items.
|
Item |
Expected Result |
Follow-up Operation |
|
Check the connection between the local and remote interfaces. |
The local and remote interfaces are properly connected using a cable. |
If the local and remote interfaces are not properly connected, reconnect them. If the fault persists, change the cable between the two interfaces. |
|
Run the display dsl interface command in the system view to check the binding mode of G.SHDSL interfaces, number of the main interface, and number of bound interfaces. |
The value of the Port bind status field indicates the interface binding status: l Normal: indicates that the G.SHDSL interface is not bound. l MPair-X: indicates M-Pair binding. X specifies the number of bound interfaces. l EFM-X: indicates EFM binding. X specifies the number of bound interfaces. The Bind group master port field indicates the main interface. The requirements are as follows: l The local and remote G.SHDSL interfaces use the same binding mode. l The numbers of bound interfaces on both ends are the same. l The main interfaces on both ends are the same. |
If the binding modes of the G.SHDSL interfaces, main interfaces, or numbers of bound interfaces on both ends are different, perform the following operations: 1. Run the following commands on the four G.SHDSL interfaces: l Run the shutdown command to shut down the interfaces. l Run the undo shdsl bind command to delete the binding configurations from the interfaces. 2. Run the set workmode slot slot-id shdsl { atm | ptm } command in the system view to change the local binding mode to be the same as the remote binding mode. 3. Find the local main interface according to the remote main interface. Run the shdsl bind command on the local main interface to change the local bound interface quantity to be the same as the remote bound interface quantity. |
If "Atm1/0/0 current state : DOWN" is still displayed, go to step 5.
l If "Atm1/0/0 current state : UP" is displayed, ATM1/0/0 is in the Up state. Go to step 2.
Step 2 Check that the local and remote G.SHDSL interfaces use the same transmission standard.
Run the display dsl interface command in the system view to check the transmission standard of the G.SHDSL interfaces. The value of the Port transmission mode field indicates the transmission standard.
l If the local and remote G.SHDSL interfaces use different transmission standards, run the shdsl annex command on the local G.SHDSL interface to change its transmission standard to be the same as the transmission standard of the remote G.SHDSL interface.
l If the local and remote G.SHDSL interfaces use the same transmission standard, go to step 3.
Step 3 Check that the local and remote G.SHDSL interfaces work in the same PSD mode.
Run the display dsl interface command in the system view to check the PSD mode of the G.SHDSL interfaces. The value of the Port power spectral density field indicates the PSD mode.
l If the local and remote G.SHDSL interfaces work in different PSD modes, run the shdsl psd command in the G.SHDSL interface view to change its PSD mode to be the same as the PSD mode of the remote G.SHDSL interface.
l If the local and remote G.SHDSL interfaces work in the same PSD mode, go to step 4.
Step 4 Check that ATM is correctly configured.
l If IP packets are transmitted over ATM links, check the following items.
|
Item |
Expected Result |
Follow-up Operation |
|
Run the display this command in the G.SHDSL interface view to check whether the IP address of the local G.SHDSL interface is on the same network segment as the IP address of the remote interface. |
IP addresses of the local G.SHDSL interface and the remote interface are on the same network segment. |
If IP addresses of the local G.SHDSL interface and the remote interface are on different network segments, run the ip address command in the G.SHDSL interface view to assign the local G.SHDSL interface an IP address that is on the same network segment as the IP address of the remote interface. |
|
Run the display this command in the ATM-PVC view to check whether IPoA mapping is correctly configured on the PVC. |
The mapped IP address is the IP address of the remote interface. |
If the mapped IP address is not the IP address of the remote interface, run the map ip command in the ATM-PVC view to configure the IP address of the remote interface as the mapped IP address. |
l If IPoE packets are transmitted over ATM links, check the following items.
|
Item |
Expected Result |
Follow-up Operation |
|
Run the display this command in the VE interface view to check whether the IP address of the local VE interface is on the same network segment as the IP address of the remote interface. |
IP addresses of the local VE interface and the remote interface are on the same network segment. |
If IP addresses of the local VE interface and the remote interface are on different network segments, run the ip address command in the VE interface view to assign the local VE interface an IP address that is on the same network segment as the IP address of the remote interface. |
|
Run the display this command in the ATM-PVC view to check whether IPoEoA mapping is correctly configured on the PVC. |
IPoEoA mapping is correctly configured. |
If IPoEoA mapping is incorrectly configured, run the map bridge command in the ATM-PVC view to reconfigure it on the PVC. |
l If PPP packets are transmitted over ATM links, check the following items.
|
Item |
Expected Result |
Operation |
|
Check whether the local VT interface and the remote interface have the same PPP user name and password. |
The local VT interface and the remote interface have the same PPP user name and password. |
If the local VT interface and the remote interface have different PPP user names or passwords, run the ppp pap local-user or ppp chap password command in the VT interface view to change the PPP user name and password of the local VT interface to be the same as those of the remote interface. |
|
Run the display this command in the ATM-PVC view to check whether PPPoA mapping is correctly configured on the PVC. |
PPPoA mapping is correctly configured. |
If PPPoA mapping is incorrectly configured, run the map ppp command in the ATM-PVC view to reconfigure it on the PVC. |
l If PPPoE packets are transmitted over ATM links, check the following items.
|
Item |
Expected Result |
Follow-up Operation |
|
Check whether the local dialer interface and the remote interface have the same PPP user name and password. |
The local dialer interface and the remote interface have the same PPP user name and password. |
If the local dialer interface and the remote interface have different PPP user names or passwords, run the ppp pap local-user or ppp chap password command in the dialer interface view to change the PPP user name and password of the local dialer interface to be the same as those of the remote interface. |
|
Run the display this command in the ATM-PVC view to check whether PPPoEoA mapping is correctly configured on the PVC. |
A correct VE interface is specified. |
If an incorrect VE interface is specified, run the map bridge command in the ATM-PVC view to correctly configure PPPoEoA mapping on the PVC. |
If the fault persists, go to step 5.
Step 5 Collect the following information and contact technical support personnel.
l Results of the preceding troubleshooting procedure
l Configuration files, log files, and alarm files of the device
----End
