Which OSI layer is responsible for routing packets and determining the best path across a network?

The Network layer is responsible for routing packets and determining the best path across a network. This layer plays a crucial role in facilitating communication between different networks. It manages logical addressing, which allows data to be directed to the correct destination by using addresses such as IP addresses.

In the context of its functions, the Network layer deals with packet forwarding through routers and handles the selection of paths based on conditions such as network congestion, the status of the links, and the overall topology of the network. This makes it essential for establishing routes so that data can move efficiently from one source to one or more destinations, enabling diverse networks to communicate with each other.

The other layers serve different functions: the Session layer manages sessions between applications, the Data link layer handles the physical addressing and access to the physical transmission medium, and the Transport layer is responsible for end-to-end communication and ensuring complete data transfer with reliability. Each layer has its specific role, but the functionality of routing and path determination is distinctly assigned to the Network layer.