Differences

This shows you the differences between two versions of the page.

--- adsl:troubleshoot [2010/11/12 13:53] – mats
+++ adsl:troubleshoot [2010/11/26 14:00] (current) – mats
@@ Line 5: / Line 5: @@
 =====  =====
 **.** (one dot)\\
-Power on, idle - no DSLAM has been detected.
+Power on, idle - no DSLAM has been detected. [[wp>DSLAM]]
 **..** (two dots)\\
@@ Line 14: / Line 14: @@
 ======  ======
-To troubleshot the ADSL connection:
+To troubleshoot the ADSL connection:
   - Turn on the Internet Gate and wait for a couple of minutes.
@@ Line 25: / Line 25: @@
 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.
-  - 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 =====
+When the modem starts to negotiate, one rolling figure-of-eight is displayed on the frontpanel.
+From now on one can also follow the progress on the [[web_gui:adsl_status_page|ADSL Status]] page, in the **ADSL line state** report.
+If this first ADSL training step is successful, it is followed by a second figure-of-eight on the display, then a third, at which the ADSL link normally will be successfully established.
+By this time you should have a full frequency diagram on the [[web_gui:adsl_status_page|ADSL Status]] page, the **ADSL line state** should be //Active// and the transmit and receive speeds (displayed on the [[web_gui:adsl_status_page|ADSL Status]] page as well) should be as expected.
+You should also now get a "line: link up" message in the [[web_gui:system_log_page|system log]].
+The display now shows one rolling figure-of-eight, accompanied by the text "''**IP**''", which indicates that the modem starts getting its IP address.
+This should not go on for very long, after some seconds (up to a minute) it should have got its IP address, and the display will shift to one of the steady texts ''**Hi**'', ''**Lo**'' or ''**AC**''.
+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.
+\\
+\\
+\\
+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.