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OSI Model Explorer

Interactive guide to all 7 OSI layers — protocols, devices, common issues, and troubleshooting tools

The OSI (Open Systems Interconnection) model is a conceptual framework that divides network communication into 7 layers.Each layer has a specific responsibility and communicates with the layers directly above and below it. Click any layer to expand it and see protocols, devices, common issues, and troubleshooting commands.

Memory Aids

Top → Bottom (7→1):“All People Seem To Need Data Processing”

Bottom → Top (1→7):“Please Do Not Throw Sausage Pizza Away”

Click a layer to expand it

Quick Reference

Layer	Name	PDU	Example Protocols
L7	Application	Data	HTTP / HTTPS, FTP / SFTP, SMTP / IMAP / POP3
L6	Presentation	Data	TLS / SSL, JPEG, MPEG
L5	Session	Data	NetBIOS, RPC (Remote Procedure Call), SMB session layer
L4	Transport	Segment (TCP) / Datagram (UDP)	TCP (Transmission Control Protocol), UDP (User Datagram Protocol), SCTP (Stream Control Transmission Protocol)
L3	Network	Packet	IPv4, IPv6, ICMP (ping, traceroute)
L2	Data Link	Frame	Ethernet (IEEE 802.3), Wi-Fi (IEEE 802.11), PPP (Point-to-Point Protocol)
L1	Physical	Bit	Ethernet (physical signalling, 10BASE-T, 100BASE-TX, 1000BASE-T, etc.), IEEE 802.11 (Wi-Fi physical layer), DSL