What Is The Lowest Layer Of The Osi Model At Which Lans And Wans Support The Same Protocols?

What Is The Lowest Layer Of The Osi Model At Which Lans And Wans Support The Same Protocols?

The network layer is the lowest layer of the OSI model at which LANs and WANs support the same protocol. Today, let us discuss the network layer of the OSI model in detail. The network layer is layer 3 of the OSI model. Layer 3 is mostly responsible for the routing of the packets from one device to another device across the network.

The main services that are provided at the network layer are fragmentation and reassembly, logical addressing, encapsulation, routing, logical addressing, and handling of the errors.

Now, let us discuss each service in detail. The first is logical addressing, in logical addressing each device must consist of a logical address to communicate every device. The logical addressing can be performed by IPv4 and IPv6.

Now, we assign the logical address to each device so that they can able to communicate with the other device, the assigning of the addresses can be done statically or it can be done dynamically.

The network layer of the OSI model uses the IP address and layer 2 that means the data link layer uses the mac address. The mac address can also be considered as the hardware address. The assigning of the addresses can be done via DHCP servers.

The IPv4 is the most used protocol in recent times, it is a 32-bit address that can be available for over 19 million users but still, it is not sufficient due to an increase in traffic. The stricture of IPv4 address consists of numerals that are separated by the dots.

Due to scarcity in the IPv4 address, the IPv6 has come into the field. The IPv6 is a 128-bit address that consists of both numerals and alphabets. The stricture of the IPv6 address is alphanumeric that is separated by the colons.

Another type of service is routing and encapsulation. Now, let us discuss each of them in detail. The appending from layer 4 to layer 3 by the router is called routing. And the sending of the data to layer 2 is called encapsulation.

The header of layer 3 consists of the IP address so that they can know where the data is going to and from where the data is coming from. The routing finds the best path from the source to the destination address to send the data through the best path.

The network layer also provides the fragmentation and the reassembly, now let us know each of them in detail. After performing the encapsulation when the data is passing through the data link layer, the message or data can be too long in some cases. So the message is divided into different fragments. After dividing the message into multiple fragments, these multiple fragments are then reassembled at the arrival of the destination network layer. The maximum payload size for ethernet is 1500 bytes. The layer three devices will split into the form of the fragments after it reaches to the destination address, the fragments get reassembled.