At which OSI model layer do hubs and repeaters function?

Hubs and repeaters operate at the Physical Layer of the OSI model. This layer is responsible for the physical connection between devices, including the transmission and reception of raw binary data over a physical medium. Hubs function by receiving electrical signals and broadcasting them to all ports, without interpreting the data. Repeaters amplify and regenerate signals to extend the transmission distance over cabling.

Understanding the role of the Physical Layer helps clarify why hubs and repeaters fit here. They do not concern themselves with the formatting, addressing, or integrity of the data, which are functions of higher layers in the OSI model. Ultimately, both hubs and repeaters strictly deal with the basic function of transmitting signals, characterizing their position firmly in the Physical Layer.