Computer Science – 14.1 Protocols | e-Consult

The Network layer and the Data Link layer in the OSI model work together to ensure reliable data transmission across a network. The Network layer (Layer 3) is responsible for logical addressing (IP addresses) and routing packets between different networks. The Data Link layer (Layer 2) handles physical addressing (MAC addresses) and framing data for transmission over a specific physical link.

Here's a diagram illustrating the data encapsulation process:

The data encapsulation process begins at the Application layer. Data is passed down through the layers. When data reaches the Network layer, the IP header is added, creating a packet. This packet is then passed down to the Data Link layer. The Data Link layer adds a header and trailer containing the source and destination MAC addresses, forming a frame. The frame is then transmitted over the physical medium. At the receiving end, the process is reversed – the frame is received by the Data Link layer, the header and trailer are removed, and the packet is passed up to the Network layer, and so on, until the original data reaches the Application layer.