So if you have copper cable phone lines to your telecoms cabinet (typical UK BT OpenReach setup not Virgin Cable), disconnecting any and all your phone extension sockets in the property and having your router plugged into the master socket can see a doubling of speed! Its possible to have router establish a speed that is faster than your broadband package offers, so you will be throttled back to the speed you are paying for.

Some routers will also highlight if there is interference on the line, which makes it harder to calculate how long the cable from your property to the cabinet can be. Some routers will also show who the cabinet manufacturer is and firmware version, usually Broadcom or reportedly Huawei, but I've not found a Huawei cabinet yet. I've found German routers to be best.

The new cabinets also reportedly emit an independent radio signal in case the line to the cabinet goes down which might also be used to detect when someone has opened the cabinet. Anyone could mess around with the older telecoms cabinets! So monitoring the RF with a SDR could throw up more interesting data.

And then its off to your exchange where companies like TalkTalk also run their own cabling so you may not be on the BT OpenReach network, especially if you are a TalkTalk customer. I'm not aware of ISP using both OpenReach and TalkTalk but some arrangements might exist.

And then from there, if the problem is not between your exchange and your property, then sometimes using a VPN service into another country can help for those situations where the usual route to your popular sites are congested/problematic, ie VPN to a different country so that you can come in to the US from the West coast instead of the East coast, or VPN to German in order to access a Swiss website, instead of France to Switzerland.

(Submarine) Cable maps can be handy for working out the countries to VPN into to get a different route into a country and thus favoured websites.