You and your business depend on the Internet
daily for everything and anything. But do you
know how it really works?
Site(s) To Your
ISP's Core Network
To connect you to the Internet, your Internet
Service Provider (ISP) creates a link between your
site(s) and its own core network, probably by
using one or more of the following technologies…
Data is sent over a copper phone line to the local telephone
exchange. From there, the data travels via fibre-optic cables to
your ISP's core network. The maximum speed varies widely by
location and the upload speed is fairly low. ADSL is ideal for very
small offices and for staff that work from home.
Think of this as ADSL on steroids. It offers
faster speeds, because it uses more fibre-
optic cabling and shorter distances of copper.
It's not as widely available as ADSL.
Fibre To The Cabinet (FTTC)
A distant cousin of ADSL. EFM uses between 2 and 8
phone lines, instead of just one. The upload speed
matches the download speed. Most EFM connections are
'uncontended' meaning you won't have to fight other
customers for a limited amount of bandwidth.
Ethernet First Mile (EFM)
2 to 8 bonded
Customer Office Local Exchange
These use fibre-optic cabling for the entire
route. They offer the fastest connections and
the most reliable links. They are a very popular
choice for connecting offices to the Internet.
Leased lines are uncontended.
Fibre Leased Lines
Which connection option is right for your
business? That depends on your bandwidth
requirements, the amount of data you're
transferring each month, your budget and the
options available in your location.
• The Internet can feel like one single network, but
it is really made up of separate networks – over
52,000 of them.
• Some of these networks, or to use the proper
term - Autonomous Systems (AS), can connect to
each other with the help of Internet peering.
One network, two networks, three networks…
• Peering occurs when two Autonomous Systems transfer data to each
other directly. It happens mostly in large data centres within major cities.
• Network operators that want to peer can join an Internet Exchange
(abbreviated IX). These make it simpler for network operators to swap
traffic with fellow member of the same Internet exchange.
• Examples of Internet Exchange Points (IXPs):
• Unfortunately, there are only a few
hundred ISPs at most Internet
exchanges, so it’s not practical for
your ISP to connect to the whole
Internet through peering alone.
• This is where Internet transit comes
in. In return for a hefty 'transit' fee,
a few international telecoms firms
are willing to fill in the gaps, acting
as a bridge between your ISP and
the rest of the Internet.
• Your ISP can connect you to the
whole of the Internet by using a
mixture of peering and transit.
• How does an ISP know where to send your requests? By using DNS and BGP.
• If I visit Google UK's web site, my computer uses the Domain Name System (DNS)
to convert the hostname www.google.co.uk into an IP address, 22.214.171.124.
• My ISP then needs to route my request for Google's homepage to the correct
section of the Internet.
• Luckily for me, Autonomous System 15169 is announcing to the world (via Border
Gateway Protocol) that it is happy to receive requests intended for IP addresses in
the range 126.96.36.199 to 188.8.131.52. As 184.108.40.206 falls within that range,
my ISP will send my request for www.google.co.uk to that Autonomous System.
• My ISP has an Autonomous System (AS 39326) that peers with AS 15169, so my
request for Google UK's homepage goes directly to Google, without having to pass
through the network of a transit-providing middle man.
You now know how your business connects to
the Internet. But how can you ensure it stays
Check whether your Internet connection comes
with a Service Level Agreement (SLA). This
document guarantees that your Internet
connection will only ever experience minimal
downtime. It also explain how you'll be
compensated if the service you receive falls short
of agreed levels.
If your business is heavily reliant on its Internet
connection, you should consider installing a backup
Internet connection. This doesn't need to be
expensive. The connection just has to be good
enough to tide you over until your main connection
One tip for getting problems fixed faster is to sign up for
an Internet service that offers 24x7 support. That way,
troubleshooting takes place throughout the day and
night. Network upgrades, patching and rebooting can
be scheduled at times of the day when no-one from
your organisation is around to notice disruption.
Another way to cut downtime is to use an ISP
that monitors its customer connections for
problems. This allows your ISP to begin
troubleshooting some problems that you've yet
to notice or report.
Do you need help with your
Contact us today for a chat:
+44 (0) 20 7847 4510