All right, so since there's really nothing much to say about the physical layer, I mean, because
in this course, we're really looking at the digital side of networking.
I'd like to just skip that and start with the second one, the datalink layer.
The datalink layer is the second layer and the U.S. Open Systems Interconnection seven layer reference
model.
Now it responds to service requests from the network layer above it and issues service requests to the
physical layer below it.
Right.
So the datalink layer is responsible for encoding bits into packets prior to transmission and then decoding
the packets back in the bits at the destination.
And bit, by the way, are the most basic unit of information in computing and communications.
Packets are the fundamental unit of information transport in all modern computer networks and increasingly
in other communications networks as well.
So the datalink layer is also responsible for.
Logical link, control media access control hardware, addressing error detection and handling and defining
physical labor standards.
It provides reliable data transfer by transmitting packets with the necessary synchronization error
control and flow control.
The data link layer is divided into two sub layers.
First, the media access control, MAK subletter, the governor's protocol, access to the physical
network medium through the Mac addresses that are typically assigned to all ports on a router, multiple
devices on the same physical link can uniquely identify one another at the data link layer.
Mac addresses are used in addition to the network addresses that are typically configured manually on
ports within a network.
Now, secondly, the logical link control, or LLC subletter, manages communications between devices
over a single link of a network.
This subletter supports fields in link layer frames that enable multiple higher layer protocols to share
a single physical link.
So here we have some protocols and the datalink layer and some physical media and connection methodologies
in the physical layer.
Ethernet and Aido to dot one one wireless lan are the best known protocols of the datalink layer.
Ethernet is the name of the most commonly used network protocol that controls how data is transmitted
over land, which is a local area network.
Now you need to have a network interface card in the device that you want to connect to the network.
I know it probably seems pretty obvious to you, but I just wanted to make sure that we're all on the
same page.
A wireless local area network, or LAN, is a wireless computer network protocol that links two or more
devices using wireless communication within a limited area such as a home or school computer lab or
office building.
And this gives users the ability to move around within a local coverage area and still be connected
to the network.
Most modern lands are based on the eye Tripoli Aido to one one standard and are marketed under the Wi-Fi
brand name.