What makes the internet possible are network-to-network connections. The “network layer” takes part in carrying out the internet communications process and makes these connections possible to send and receive the data packets between different networks.
In the 7-layer OSI model, which we will discuss later, the network layer comes at no. 3. One of the main protocols used at this layer is the Internet Protocol (IP), along with numerous other routing, testing, and encryption protocols.
What is the network layer and how does it work?
A group of two or more interlinked computing devices is called a network. All devices in the network are typically connected to a central hub, such as a router.
A network can also have subnetworks or smaller sections of the network. This sub-networking makes it easier for large networks to manage thousands of IP addresses and connected devices, like those provided by ISPs.
The Internet can be taken as a big network of smaller networks. There are millions of computers interlinked within networks, and then these networks are connected to other networks. Through this kinking process, these computers are connected with each other regardless of the distance in between.
Every process in interworking connections is carried out at the network layer. These include route setting of data packets, examining whether a server is active on a different network, and taking into account and receiving IP data packets from other networks.
The most important of all is this last process, as the majority of the internet traffic is directed through IP.
What is a network layer example?
Suppose John and Anna are connected to a common local area network (LAN), and John wants to communicate with Anna. Due to the fact both are connected to the same network, John can send the message directly to Anna’s computer.
However, if Anna is connected to another LAN, located miles away, John’s message must reach Anna’s network first before it appears on her computer, which is a network layer process.
What are the 7 layers of the network? – OSI model
The Open Systems Interconnection (OSI) model defines how the internet works. This model divides the procedures involved to send data through seven layers over the Internet.
Each network layer function is specified for preparing the data to be transmitted through cables, wires, and radio waves in the form of bits.
It is pertinent to mention that the OSI model is a nonfigurative conceptualization of the procedures that makes the Internet work, and inferring the model and applying it to the real-world internet can be a subjective process.
The OSI model helps people talk about networking hardware and protocols, defining which protocols will be used by which hardware and software, and gives a rough idea of how the Internet works. However, it is not an inflexible step-wise definition of how Internet connections usually work.
Below are the seven layers of the OSI model.
OSI model vs. TCP/IP model
The TCP/IP model is a substitute model of how the internet operates. It divides the related processes into four layers rather than seven and uses different network-layer protocols.
While some argue that the TCP/IP model better reflects how the Internet works today, still the OSI model is widely used to understand the Internet. Both of these models have their own pros and cons.
The four layers of the TCP/IP model are given below.
You must be wondering where are layers 5 and 6 of the OSI model in the TCP/IP model. Some sources believe that the processes at layers 5 and 6 in the OSI model either are no longer needed in today’s Internet or actually fit into layers 7 and 4 (denoted as layers 4 and 3 in the TCP/IP model).
For example, you might think OSI layer 5, “sessions” is unnecessary because TCP protocol opens and keeps sessions at OSI layer 4, and it doesn’t appear in the TCP/IP model.
Also, HTTPS encryption and decryption can be regarded as an application layer process (OSI layer 7 or TCP/IP layer 4) rather than a presentation layer process (OSI layer 6).
What is the difference between the ‘network’ layer and the ‘Internet’ layer?
There is no “network” layer In the TCP/IP model. The layer in the network of the OSI model almost resembles the Internet layer in the TCP/IP model. In the OSI model, layer 3 is the network layer whereas, in the TCP/IP model, the Internet layer is layer 2.
In other words, both layers are two names of similar things, but they come from different models of internet operation.
What layer does IP use?
The most significant protocol used at layer 3 is IP or Internet Protocol. It is a standard for routing packets across different networks on the internet.
What is a packet?
A network packet is a small chunk of data sent over Transmission Control Protocol/Internet Protocol (TCP/IP) networks. A packet has two parts, a header, and a body.
What is the network layer in IoT?
The network layer is divided into two sublayers, a routing layer that handles the transfer of data packets from source to destination, and an encapsulation layer that handles forming of packets.
Like the physical and MAC layers, it is part of the infrastructure layer of the IoT reference architecture. This layer is responsible for addressing and routing data packets.
In this article, we looked at the network layer. We have also discussed the protocols at the network layer to make you well-versed with the different layers in the TCP/IP and OSI model, the difference between the ‘network’ layer and the ‘Internet’ layer, and the OSI model vs. the TCP/IP model as a whole.