UK centric broadband information and diagnostic help.

Have you turned it off and on again?

Only kidding…

One of the major gripes users have is the speed of their broadband. Bare in mind i’m mostly talking about the OpenReach network of ADSL which is typically copper  all the way to the exchange or Fibre to the cabinet (FTTC) which has a shorter run of copper from the green box into the house (voice is still copper all the way back btw).

When talking about the speed of your broadband there are two big differences to be aware of.


The speed which will usually be looked at first by your ISP first and primarily is the synchronisation speed (sync). This is the speed at which your modem / router can connect to the equipment in the telephone exchange (Central Office for our American friends) or at the green box in the street (PCP). This is the maximum speed at which data can pass down the line and shouldn’t vary too much on each reboot of your modem / router.

Things that can effect the speed are:

  • Attenuation.
  •  REIN,
  • SHINE,
  • extension wiring (further attenuation),
  • equipment  issues,
  • bridge taps,
  • poor cable shielding,
  • engineer mistakes,
  • capped profile settings on the exchange,
  • There are other causes but these are some of the most common for example.

To check your sync rate, this will involve logging onto your home router (Seek ISP support or router support for instructions) and checking the status page for connection info.


The next speed we’re interested in is the throughput speed. A good metaphor for this would be a water pipe. If the sync mentioned above is the pipe its self, throughput it was water going through it.

Lets pretend the pressure on this water pipe isn’t changeable for the sake of our metaphor 😉 

This is tricky to diagnose as as the issue can lie on the customers side as much as is can with the ISP or beyond depending on the endpoints of the testing and everything inbetween.

Various things that can effect this:

  • Fault with the sync speed (knock on effect)
  • Server on the other side not providing you with data fast enough
  • Congestion on a network (not necessarily the ISP’s).
  • Downloading on your connection while running speedtests (congesting your part of the network to give you slower, skewed results).
  • Connection to the router such as via wireless .

Testing throughput:

Here are some throughput speedtesters:


Two sockets shown here: One is a old telewest phone socket on the right and the left is a old BT (OpenReach) socket. Both have the front covers removed to show their test sockets which are inside of the right. You can see the BT one has a microfilter plugged straight into it. With a silverish cable going out of shot to the router. In the lower half of the picture we see a splitter with two cables coming out. these are going off to Sky set-top boxes. Ofter as a support engineer I would see this plugged in first and then the filter coming off of it. That would cause no end of problems as the microfilter needs to be the first device out of the socket to separate the phone frequencies from the broadband ones.


Connection Monitoring:

This is a ping monitor to my router. You either need a static IP (doesn’t change when your broadband connection drops and reconnects) or a dynamic DNS provider thats setup on your router so you can always connect back to it if the connection does drop. Such a provider is

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