I recently switched from ADSL1 to ADSL2+ (both with TPG: I’m using the Narangba exchange).

After some initial problems, I found that the modem you use can make a big difference to the speed you get.

I calculate that I’ve got about 3.5 – 4 Km of wire from my house to the exchange (Line attenuation is 52-54Db downstream, 15.5-31.4Db upstream, Noise Margin is 4-6Db downstream, 6Db upstream).

I initially had an old Billion 5102S, together with an old tp-link wr642G wireless router, but once I got adsl2+, the internet would usually drop out between 1 and 5 times a day, and although it said the downstream speed was about 4000 kbps, It would often feel slower than my old 1500kbps ADSL1 connection.

After a few weeks, I decided to get a newer, all-in-one, wireless modem router. I do some research, and I read good things about the billion 7300G, but after installing it it still doesn’t work right.

About once or twice a day, it would spontaneously reset, and it still felt slow.

I eventually returned it (as I figured it was faulty).

While waiting for a replacement for the 7300g, I decided to install a netgear DG834G v3

I was amazed that the dg834G actually connected at 4700kbps! And, it generated a lot less dropouts, and no resets, and the internet actually felt fast (most of the time)

I wouldn’t have thought that the modem type would make much difference, but there you go!

I’ve since heard that some modems do well close to the exchange (less than 2 Km), while others are better at longer distances.

Once I got the replacement 7300G, I noticed that it would still dropout and reset (but not as often as the original).

After some research, and some experimenting, I found that I could make it much more stable by altering the ADSL settings (configuration -> WAN -> ADSL).

I changed the adsl mode to annex A (was open annex)

I also changed the modulator to ADSL2 (was auto).

I experimented with some of the other adsl modes (annex L, and annex M), but with no difference in upstream speeds.

I also tried some other modulator types (ADSL2+ would cause the modem to reset occasionally, and G.DMT was slightly slower than ADSL2).

With the current settings, the modem resets about once per week, and the adsl sync is lost every 1 to 2 days… Not bad, considering ADSL2+ seems to have a reputation for many dropouts once you are over 3Km from the exchange!