Which layer of the OSI model is primarily concerned with how data packets are routed through the network?

The layer of the OSI model that is primarily concerned with how data packets are routed through the network is the Network layer. This layer is responsible for determining the best path for data transmission from the source to the destination across multiple links and routers. It handles logical addressing, typically using IP addresses, and facilitates routing protocols that manage the packet's journey through the network topology.

For instance, when data packets are sent from one device to another over the Internet, the Network layer is responsible for breaking down that transmission into packets, addressing those packets for delivery, and ensuring that they are routed through various intermediate devices (such as routers) using routing algorithms. This functionality is crucial for effective communication in any complex network setup, such as those found in enterprise environments or the global Internet.

Understanding the role of the Network layer also highlights why the other layers do not perform these tasks. The Data Link layer focuses on local network delivery, managing physical addresses (MAC addresses) within a single local area network (LAN) segment. The Transport layer ensures reliable communication between end systems through error correction and flow control but does not deal with routing packets. Lastly, the Physical layer is concerned with the actual transmission of raw bitstreams over physical mediums, without addressing the broader network communication needs