Route congestion and message priority are a few of the functions of what layer of the OSI Model?

Layer 1 (Physical) only handles raw bit transmission over physical media and has no awareness of routing or priority.

Layer 2 (Data Link) handles frame delivery within a single network segment using MAC addresses, not inter-network routing or congestion control.

Layer 3, the Network Layer, handles routing of packets between networks, congestion management, and quality-of-service priority assignments. It uses logical addresses (like IP addresses) to determine the best path for data, and it controls traffic flow to prevent congestion on network links.

Layer 4 (Transport) manages end-to-end communication, segmentation, and reliability, but routing and congestion at the network path level belong to Layer 3.

Layer 5 (Session) manages establishing, maintaining, and terminating communication sessions between applications, not routing or message priority.