| Layer | Protocol data unit (PDU) | Function[1] | ||
|---|---|---|---|---|
| Host layers |
7 | Application | Data | High-level protocols such as for resource sharing or remote file access, e.g. HTTP. |
| 6 | Presentation | Translation of data between a networking service and an application; including character encoding, data compression and encryption/decryption | ||
| 5 | Session | Managing communication sessions, i.e., continuous exchange of information in the form of multiple back-and-forth transmissions between two nodes | ||
| 4 | Transport | Segment, Datagram | Reliable transmission of data segments between points on a network, including segmentation, acknowledgement and multiplexing | |
| Media layers |
3 | Network | Packet | Structuring and managing a multi-node network, including addressing, routing and traffic control |
| 2 | Data link | Frame | Transmission of data frames between two nodes connected by a physical layer | |
| 1 | Physical | Bit, Symbol | Transmission and reception of raw bit streams over a physical medium | |
- ^ "Windows Network Architecture and the OSI Model". Microsoft Documentation. Retrieved 24 June 2020.