The OSI model is a means of grouping protocols by the layer at which they operate.
|7||Application||Primary interface for working with a communication system||FTP, [[HTTP||net.http]], SSH|
|6||Presentation||Formatting and presentation of data; e.g. encoding, data compression, encryption/decryption||ASCII, PNG|
|5||Session||Managing communication sessions (continuous transmissions between two nodes)||SYN, ACK, source and destination ports|
|4||Transport||Reliable transmission of data segments between points on a network, including segmentation, acknowledgement and multiplexing||[[TCP||net.tcp]], [[UDP||net.udp]], [[port numbers||net#common-port-numbers]]|
|3||Network||Structuring and managing a multi-node network, including addressing, routing and traffic control||IP ([[v4||net.ipv4]] and [[v6||net.ipv6]]), routers|
|2||Data link||Reliable transmission of data frames between two nodes connected by a physical layer||[[Ethernet||net.ethernet]], MAC, switches|
|1||Physical||Transmission and reception of raw bit streams over a physical medium||[[Ethernet||net.ethernet]], Twisted pair, optical fiber, RJ45|