I live 600 m from an ADSL2+ cabinet and the best speedtest.net results I have are 10 Mbps downstream and 0.63 kbps upstream. Attenuation is 19.5 dB down and 7.9 dB up. This indicates I should be 1.4 km from the cabinet rather than the measured 600 m in a direct line down the street (attenuation divided by 13.8).
I've managed to eek out a better upload speed by switching to a TP-Link TD8840 router with a Broadcom chipset (0.45 to 0.63 Mbps), but I figure I should be able to get up to 20 Mbps down and 1 Mbps up considering the distance to the cabinet.
Is it worth having my internal wiring looked at to see if this is the cause of lower than expected speeds? I have naked DSL and the incoming line branches out to seven phone jacks, one of which has the ADSL router plugged in. The other six jacks are connected to my wiring but there are no devices plugged in. I'm wondering if the lines to the six inactive jacks should be cut. How much of an issue is messy internal wiring?