TCP/IP Model

In this blog post the TCP/IP Model is looked at to give an overview of how it operates and how data moves through it. Examples are given of each layer of the TCP/IP Model.

TCP/IP Model

The TCP/IP model is made up of layers:

Data is encoded and decoded at Application layer.

Data is split into chunks in the Transport layer.

Data has addressing added to it in the Internet layer.

Data is transmitted in the Link layer.

Adding in Protocols

The network protocols previously looked at can be added into the TCP/IP model to show the layer they operate at:

Internet Layer

The Internet Layer is where the Internet Protocol takes place. Internet Protocol is implemented in two versions IPv4 and IPv6, i.e. IP version 4 and IP version 6.

IPv4 addresses are in the format of 4 octets with decimal values up to 255 in each octet. They look like:

• 10.0.0.1
• 127.0.0.1
• 192.168.1.1

IPv6 addresses are in the format of eight groups with four hexadecimal in each group. They look like: 2001:0db8:0000:0000:0000:8a2e:0370:7334

The Internet Layer adds the senders address and recipients address, so it knows where to send data to and where data came from.

Link Layer

The Link Layer is where protocols such as Ethernet (e.g. ethernet cables) and IEEE 802 (e.g. WiFi) are. The Link Layer enables the transfer of packets between nodes on a network.

Putting It All Together

Now that we have some examples for Internet Layer and Link Layer they can be added into the table: