Layer 1 in the Open Systems Interconnection (OSI) model is the Physical layer. This layer is responsible for the physical transmission of data over a network, handling the raw bits of data and their transmission across the physical medium. It defines the electrical and physical specifications of the network, such as the type of cables, connectors, and signaling methods used. The physical layer does not deal with data formatting or interpretation, only with the physical transmission of data.
Examples of functions performed by the physical layer:
- Encoding and decoding of signals: Converting data into electrical signals that can be transmitted over the network and vice versa.
- Physical addressing: Identifying devices on the network using physical addresses like MAC addresses.
- Signal timing: Ensuring that data is transmitted and received at the correct speed.
- Media access control: Regulating the use of the physical medium by different devices.
Examples of devices that operate at the physical layer:
- Network interface cards (NICs)
- Ethernet hubs
- Network switches
- Repeaters
In summary, Layer 1 is the foundation of the OSI model, providing the physical infrastructure for data transmission.
