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Troubleshooting
This shows you the differences between two versions of the page.
adsl:troubleshoot [2010/11/25 16:59] mats |
adsl:troubleshoot [2010/11/26 14:00] (current) mats |
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===== ===== | ===== ===== | ||
**.** (one dot)\\ | **.** (one dot)\\ | ||
- | Power on, idle - no DSLAM has been detected. | + | Power on, idle - no DSLAM has been detected. [[wp>DSLAM]] |
**..** (two dots)\\ | **..** (two dots)\\ | ||
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If the modem has been in contact with a DSLAM (two or three dots) but could not maintain a connection, or could not transmit data on the connection, then you need to check: | If the modem has been in contact with a DSLAM (two or three dots) but could not maintain a connection, or could not transmit data on the connection, then you need to check: | ||
- VCI/VPI values on the [[:web GUI:Network page#Access type|Network page]] must match your Internet Provider's values. | - VCI/VPI values on the [[:web GUI:Network page#Access type|Network page]] must match your Internet Provider's values. | ||
- | - ADSL mode on the [[:web GUI:ADSL page]] must match the ones used be the DSLAM at the other end of the connection | + | - ADSL mode on the [[:web GUI:ADSL page]] must match the ones offered by the DSLAM at the other end of the connection |
- | - ADSL standard on the Advanced [[:web GUI:ADSL page]] must match the ones used be the DSLAM at the other end of the connection | + | - ADSL standard on the Advanced [[:web GUI:ADSL page]] must match the one used by the DSLAM at the other end of the connection |
===== Training, retraining and disconnecting ===== | ===== Training, retraining and disconnecting ===== | ||
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If this never seems to happen, see the [[troubleshooting:internet_access_problems|internet access problems]] page for how to carry on the troubleshooting. | If this never seems to happen, see the [[troubleshooting:internet_access_problems|internet access problems]] page for how to carry on the troubleshooting. | ||
It may be a problem with the VPI/VCI settings or some DHCP or PPPoE/PPPoA problems. | It may be a problem with the VPI/VCI settings or some DHCP or PPPoE/PPPoA problems. | ||
+ | \\ | ||
+ | \\ | ||
+ | \\ | ||
+ | The ADSL connection, when successfully established, will stay up "forever" as long as the modem is powered on. | ||
+ | However, disturbances can happen on the telephone line that may force the modem to drop the link and to retune to the apparently noisy line. | ||
+ | In the ADSL language this is a //retrain//. | ||
+ | This is visible on the display: the ''**Hi**'', ''**Lo**'' or ''**AC**'' text disappears and is replaced by one or more dots (see above).\\ | ||
+ | In the [[web_gui:system_log_page|system log]] there is now a message | ||
+ | line(line): Link down. | ||
+ | accompanied by one or more lines telling, in technical terms, the causes of the link drop. For example: | ||
+ | ADSL: local loss of signal error | ||
+ | ADSL: local severely errored frames error | ||
+ | |||
+ | It is not always clear what causes such a disturbance. | ||
+ | Surprisingly often, the fault is actually to be found at the customer's premises (i.e. inside your own building): | ||
+ | * Is the ADSL connector and the [[adsl:start#Splitter|splitter]] properly connected?\\ :!: Generally, the ADSL modem should be connected to the 1:st (main) phone jack to get as clean signal as possible. | ||
+ | * Are there more devices, apart from phones, attached to this telephone line, such as fax machines, answering machines etc? If so, try disconnecting them one at a time to see if the problem disappears. | ||
+ | * Are there any disturbing appliances in the //very// close vicinity of the modem and its ADSL cable? | ||
+ | If no obvious source for the disturbance is to be found, and it happens frequently, the Internet (or ADSL line) provider's support should be consulted. | ||
+ | The advanced user may consider to use the **Force SNR Margin** or even disable the **Retrain** parameter, see the [[web_gui:adsl_page#Advanced|ADSL settings]] page. | ||
+ | |||
+ | After a link drop the modem will constantly try to establish the connection again, without any user intervention: | ||
+ | * If the dots remain on the front panel display, there is a constant disturbance or a broken cable connection that must be fixed. | ||
+ | * If the retrain is successful and the link is established, the rolling figure-of-eight plus "''**IP**''" reappears and the modem starts renewing its IP address again, as has been described above. | ||