Broadband help and support

This page is simply a landing page for links I find interesting / useful regarding broadband technology.
This page will also be pretty UK centric. Please share / tweet / like the page if you find it helpful. Thanks!

If you'd like me to add some further links, please leave a comment at the bottom of the page.

---------------------- Reference links --------------------------

Speed calc -
What is SNR? -
What is SNR margin? -
Attenuation -
Interleaving -
Error correction -

ADSL Nation:

British Telephone sockets

Think Broadband

Bandwidth Calculator

Broadband forum (technical reports)

Info On Forward error correction (FEC),11585082

Sam knows exchange checker.

General technical DSL info:

This site contains information about BT's networks and services. (Check Sin 349 & 498 (FTTC))

Open Reach document on CIDT (Coper Integrated Demand Testing)

Open Reach Document on demarcation points (master sockets, Network terminating Point)

G.992.5 ITU specification:

Acatel Lucent

ADSL Nation
Here you can get very good quality face plates / filters for your broadband.

PSD info - texus instruments

OUI Lookup tool

Ripe IP database query

Pictures inside an exchange:

Carrier grade NAT:

WiFi analyser (InSSIDer):

Master socket wiring:

ISP support pages:
Talk Talk

--------------------About broadband speeds-----------------------

When talking about the speed of your broadband there are two big differences to be aware of.
1. Speed which will usually be looked at first by your ISP 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). 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 REIN, SHINE, extension wiring, exchange issues, bridge taps, engineer mistakes, capped settings on the exchange. There are other causes but these are some of the most common for example.

2. The next speed we're interested in is the throughput speed. A good metaphor for this would be a water pipe. If the sync is the pipe its self, throughput it was water going through it. This is tricky to diagnose as as the issue can lie on the customers side as much as is can with the ISP.

Various things that can effect this are: 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 results), connection to the router such as via wireless.

Here are some throughput speedtesters:


Here is a link to a PDF with router logins where you can check you sync speed.

Some example outputs:

My Broadband Speed Test


Below is an image of a BT OpenReach NTE5 socket next to a very similar Telewest socket. Both appear to have test sockets. We can see here that a microfilter is in the BT OpenReach test socket.

 In the bottom left we can see a Sky TV extension splitter which has been temporarilty disconnected. This would usually plug into the phone side of the microfilter, not before the broadband filter where it can cause problems!  

In the picture below we can see some self install parts for an NTE5. The one on the left is a I Plate which goes in between the front cover and the back (Does not include a micro-filter). On the right is a ADSL nation XTE-2005 faceplate with a built in micro-filter.

Below has the XTE-2005 on the right and the I plate on the left. 

---------------------------Ping monitors ---------------------------

There are some services / products such as SmokePing and FireBrick that will ping the address your router gets given by your ISP and will measure the response time, packet loss or if there is no response at all. These services are typically for a connection with a static IP that does not change.

Here is an example of a TalkTalk Business line I have:

My Broadband Ping - TTB fibre

This is good for monitoring a connection and also seeing if a connection has gone down. Thinkbroadband use FireBrick to provide a free service to members. Technically you could use it on a dynamic IP but you would only be able to use it for that one internet session. If your router lost connection to the ISP and reconnected you could pick up another WAN IP address.

Other tools would be using CMD on your PC to ping, trace route and pathping to popular destinations but you need a good understanding of these for them to be effective. All too often you'll see people using a tracert incorrectly.

A simpler tool would be something like the website which also tests for jitter . Makre sure nothing is using your internet connection when running these tests!


Please tweet / Like / +1 this page if you found it useful!
Please be aware that some of the documents linked may not always be the latest revision so be sure to check this if you are looking for the most up to date info.
Last edited: 28/12/2012