I've been having issues for some time now with my router, a Netgear DG834Gv3, where the ADSL connection becomes very unstable at times. The Internets suggest that this is likely due to the AR7 chipset in it arguing with whatever
Be O2 Sky use at the exchange, and losing. Netgear have gone through several hardware revisions and the v4 uses a completely different Broadcom chipset. As it happens, I've got one in the spares box.
As with all good experiments, some before and after comparison is required. So, the obligatory before statistics (with the DG834Gv3):
|Connection Speed||14502 kbps||1203 kbps|
|Line Attenuation||18 db||4 db|
|Noise Margin||3 db||5 db|
Important tip: don't try running a speed test at the same time as running inSIDDer - the searching-for-wifi-networks stuff causes frequent interruptions to the network connection and so really eats bandwidth. Presumably this is from the channel-hopping it has to do to discover the other networks.
Some reconfiguration and rewiring later, it's time to repeat with the DG834Gv4:
|Connection Speed||16307 kbps||1217 kbps|
|Line Attenuation||17.0 db||8.8 db|
|Noise Margin||6.4 db||6.8 db|
That is... quite a significant increase in both downstream sync speed, noise margin (an increase from 3dB to 6dB is actually an improvement, especially when the 3dB would go negative at times!), and real-world speed. Interestingly the upstream sync speed has increased slightly despite a large worsening in the attenuation, though in absolute terms 9dB is still very good and 1217kb/s is about as fast an upstream as ADSL2+ can do. The reported values are a lot more stable as well - with the v3, the noise margin was all over the place. Here it's varying by maybe ±0.3dB which is nothing.
And yes, I know this has nothing on Craig's ridiculous 70Mb/s connection (and note that his upstream is actually 20Mb/s!). Though BT have just wired up the local cabinet for fibre...