ADSL Settings

Internet Gate has a built-in ADSL modem capable of ADSL, T1.413, ADSL2, ADSL2+, Annex A, Annex B and Annex M.

Internet Gate is preconfigured to automatically select suitable ADSL standard and mode for communicating with the DSLAM at the other end of the ADSL connection.

Many of the decisions made about ADSL connections are made by the central DSLAM equipment at the other end of the connection and can only indirectly be affected by your local settings.

If you cannot get a working ADSL connection try to limit ADSL modes on this page to just the one you want to use, and make sure VPI/VCI on Network page is same as the DSLAM's at the other end of the connection (ask your Internet Provider for values to use).

The Internet Gate hardware is capable of connecting ADSL using both ADSL Annex A and B standards. (Annex A is over plain telephone lines, Annex B is over ISDN lines.)

Changing between Annexes A and B requires however install of different firmwares.

The Internet Gate is capable of connecting ADSL using Annex M standard, giving higher upstream (towards Internet) throughput.

Some DSLAM-s are configured to prefer plain ADSL2+ connections to Annex M connections (as they are more stabile). If the remote DSLAM refuses to use Annex M you can force it to use it by disabling all other ADSL modes checkboxes.

Most ADSL settings require current ADSL connection to be stopped and a new one started to became effective. With the Stop/Start and Restart buttons you can bring your ADSL connection down and up again.

Operational mode - ADSL technology used by the connection.

ADSL line state:

• Idle - no ADSL connection.
• Handshake - searching for ADSL connection (DSLAM), negotiating transfer protocols.
• Training - ADSL connection (DSLAM) found, test of telephone cable in progress.
• Active - ADSL connection established (Showtime). The modem is online and ready to transfer data.

For more information about the current ADSL status, see the ADSL Status page.

By default Internet Gate tries all ADSL modes to establish an ADSL connection, and remote DSLAM picks the most suitable one. By disabling some of the modes Internet Gate pretends it cannot use those modes and forces remote DLSAM to pick one of the remaining enabled ones.

Please notice that there are 4 different sets of advanced settings:

• General settings, affecting all modes
• ADSL Annex A settings (on separate page)
• ADSL2 and ADSL2+ AnnexA settings (on separate page)
• ADSL2 and ADSL2+ AnnexM settings (on separate page)

(The Annex B firmware has corresponding sets, but lacks the AnnexM mode)

Leave most settings as they are - changing them only degrades performance. Some of them however might be usable:

• Standard - select the standard used, if you know.
• Force SNR Margin - trade speed to stability. The automatic SNR margin is 6dB. Increasing it lowers throughput but increases connection stability.
• Retrain - set to “Disable” survive sporadic burst errors.