The OSI layer that directs data from one LAN to another is the Network layer (Layer 3). It is responsible for routing packets between different networks and interconnecting multiple LANs via devices like routers. Explanation and context:
- The Network layer handles logical addressing (such as IP addresses), routing decisions, and path selection to move data across disparate networks, including between LANs that are part of larger internets or WANs. This is the layer where inter-network communication is enabled, allowing data to traverse from one LAN to another through routers and other inter-network devices.
- In contrast, lower layers (Data Link Layer, Layer 2) manage node-to-node transfer within a single network segment, while the Transport Layer (Layer 4) handles end-to-end communication, reliability, and port-based multiplexing. The Network Layer’s boundary role between networks is what allows data to cross LAN boundaries.
If you’d like, I can provide a quick schematic mapping of OSI layers to typical networking devices (switches, routers, gateways) and how they interact when data moves from one LAN to another.
