What does data link layer in the OSI model primarily handle?

The data link layer in the OSI model primarily handles physical addressing and error detection. It is responsible for enabling communication between devices on the same network segment and ensuring that data is transmitted accurately over physical links. This layer adds headers and trailers to the packets to form frames, which include essential information such as source and destination MAC (Media Access Control) addresses. These addresses ensure that data is sent to the correct destination device on the local network.

Additionally, the data link layer features mechanisms for error detection and sometimes correction, ensuring that any data corruption that occurs during transmission due to noise, interference, or other issues can be identified and managed. This is crucial for maintaining data integrity as it travels across the medium.

The other options focus on different aspects of the OSI model. Data formatting for transmission is more relevant to the presentation layer, while data routing and traffic control pertain to the network layer. Application-level data processing falls under the application layer, which directly deals with end-user services and applications. Each layer of the OSI model has its unique functions, with the data link layer specifically focused on managing direct connections and the local data transfer.