Network+/Standards/OSI Model/OSI Components

This table shows the OSI model layers and the components that operate at each layer.

OSI Layer Purpose TCP/IP Layer Protocol Packet Data Unit Address Device Troubleshoot
Application Interface (API) Application HTTP, SMTP, etc. Message - - Wireshark
Presentation Formatting, Encryption, Compression Application HTTP, SMTP, etc. Message - - Wireshark
Session Authentication, Authorization Application HTTP, SMTP, etc. Message - Gateway NSLOOKUP, NBTSTAT, Wireshark
Transport Reliability Transport TCP, UDP Segment (TCP), Datagram (UDP) Port Firewall TELNET, NETSTAT, Wireshark
Network Addressing, Routing Internet IP, ICMP Packet IP Address Router IPCONFIG, PING, TRACERT, Wireshark
Data Link Logical Link Control, Media Access Control Link Ethernet, Wi-Fi, PPP, etc. Frame MAC Address Switch, Bridge, Access Point Lights on device, ARP, Wireshark
Physical Transmission Link CAT 5, RJ-45, etc. Bit - Hub, NIC, Cable, Wireless Lights on device

One easy way to remember the OSI layer is to think:[source?]

A - All

P - People

S - Seem

T - To

N - Need

D - Data

P - Processing


Another popular acrostic to remember OSI layers names is (inferring that it is required to attend classes to pass networking certification exams):

A - Away

P - Pizza

S - Sausage

T - Throw

N - Not

D - Do

P - Please


Suggestions from David Bombal (7 to 1):

A - All

P - People

S - Sleeping

T - Through

N - Networking

D - Don't

P - Pass


Going the opposite way (1-7):

P - Please

D - Do

N - Not

T - Teach

S - Students

P - Pointless

A - Acronyms


Going the opposite way, widely used in India Schools (1-7):

P - Please

D - Do

N - Not

T - Take

S - Sales

P - Person's

A - Advice