- [Instructor] The wide area network
or WAN refers to a network
that covers a large geographic area,
which may even span even across countries or continents.
The internet that we know,
or the worldwide web is a good example of WAN.
Within a WAN, we can have many other networks
that are connected to each other.
Think of it as a network of many other networks.
Say you've got a network in the US, which is then connected
to a network in Australia and Northern Singapore and the UK.
That's WAN.
That means with WAN,
we can access network devices
or servers that are remotely connected,
even on the other side of the globe.
Imagine that!
To ensure that remote networks will be able
to communicate properly with each other,
we have the WAN Standards.
The following are the authorities
that define the WAN access standards.
We've got the TIA
or the Telecommunications Industry Association,
EIA or the Electronic Industries Alliance,
ISO or the International Organization for Standardization,
and the IEEE or the Institute of Electrical
and Electronics Engineers.
The WAN standards describe both the physical
and data link requirements for a WAN connection
that covers the layers one and two of the OSI Model.
At layer one or the physical layer, we got the media type
and the interface specifications.
Meanwhile, at layer two
or the datalink layer is where
we got the various WAN protocols.
Wondering about the various WAN protocols?
Don't worry, we'll cover them separately
in the succeeding videos.
The first known wide area network was created
in the late 1950s by the US Air Force.
It was used to interconnect sites
in the Sage Radar Defense System,
connecting a huge number of dedicated phone lines,
telephones, and modems.
In today's time, we use WAN to interconnect sites
and companies across different parts of the world.
We also use WAN for remote connectivity,
much like when we work from home
or when we attend teleconferences in different countries
at different time zones.
When we search the internet,
the servers hosting the websites
that we visit could also be
in a far off place.
That is also WAN in action.
As you may see with WAN
or the Wide Area Network, we are able
to connect multiple networks together.
Otherwise, the local networks will be isolated
from each other.
But how can we connect a network to another network?
What could it look like?
That is called WAN Topology, and we'll cover that next.