SpeedTouch 516 and 585 on ADSL2+
In 2009 Bell's infrastructure did not support ADSL2+, while the modems NCF sold then, the Thompson SpeedTouch 516 and 585s, did. Because the modems defaulted to ADSL2+ and not the ADSL1 then in use on Bell's networks the modems would not connect. To fix this problem a number of modems shipped at that time were configured by NCF to force them into ADSL1 mode, which solved the problem. Now that Bell's infrastructure requires ADSL2+ for 15 MB/s service these modems that were configured that way will not work with 15 MB/s service unless reconfigured.
The configuration cannot be fixed by doing a factory reset, instead it must be done by Telnet into the modem and changing it via command line. Fortunately this is easy to do.
Linux and Mac
On Linux operating systems you can access telnet by opening a terminal and typing in "telnet 192.168.1.254" at the prompt.
On Windows XP and Vista operating systems telnet can be accessed by opening "run" and the "cmd" command and entering telnet.
In Windows 7 and 8 you can bring up the command line by entering "cmd" in the search bar.
In any version of Windows you can also run telnet by installing and using the PuTTY free software application.
Configuring the modem for ADSL2+
The commands are:
telnet 192.168.1.254 User: admin/Administrator Pass: <your dsl password>
xdsl debug multimode config=t1.413issue2+g992.1_annex_a+g992.3_annex_a+g992.3_annex_l+g992.3_annex_m+g992.5_annex_a+g992.5_annex_m
That "xdsl..." is a single command, so in copy and pasting be careful to copy the entire line without any carriage returns, which would compromise the command.