ZyXEL Communications ALC1224, User Manual

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ALC1224 User’s Guide
Troubleshooting 9-1
Chapter 9
Troubleshooting
This chapter covers potential problems and possible remedies. After each problem description, some
steps are provided to help you to diagnose and to solve the problem.
9.1 Troubleshooting Overview
See also the Integrated Ethernet Switch’s User’s Guide for additional troubleshooting information.
9.2 Data Transmission
The DSL link is up, but data cannot be transmitted.
Table 9-1 Troubleshooting Data Transmission
STEPS CORRECTIVE ACTION
1 Check to see that the VPI/VCI and multiplexing mode (LLC/VC) settings in the subscriber’s DSL
modem or router match those of the DSL port on the line card (refer to the sections on the edit port
setup screens).
Also, make sure that the subscriber’s ADSL modem is using RFC 1483 encapsulation. If the
subscriber is using a router (with routing mode), make sure it is using ENET ENCAP.
2 Check the line card’s VLAN configuration (see the chapter on VLAN).
3 Ping the line card from the computer behind the DSL modem or router.
4 If you cannot ping, connect a DSL modem to a DSL port (that is known to work) on the same line
card.
If the DSL modem or router works with a different DSL port, there may be a problem with the original
port. Contact the distributor.
5 If using a different port does not work, try a different DSL modem or router with the original port.
9.3 Data Rate
The SYNC-rate is not the same as the configured rate.
Table 9-2 Troubleshooting the SYNC-rate
STEPS CORRECTIVE ACTION
1 Connect the DSL modem or router directly to the DSL port of the line card using a different
telephone wire.
2 If the rates match, the quality of the telephone wiring that connects the subscriber to the line card
may be limiting the speed to a certain rate.
If they do not match when a good wire is used, contact the distributor.