Application layer
From Freepedia
| OSI Model | |
|---|---|
| 7 | Application layer |
| 6 | Presentation layer |
| 5 | Session layer |
| 4 | Transport layer |
| 3 | Network layer |
| 2 | Data link layer |
| 1 | Physical layer |
The application layer is the seventh level of the seven-layer OSI model. It interfaces directly to and performs common application services for the application processes; it also issues requests to the presentation layer.
The common application layer services provide semantic conversion between associated application processes. Note: Examples of common application services of general interest include the virtual file, virtual terminal, and job transfer and manipulation protocols.
| Layer | Protocols |
|---|---|
| Application | FTP, HTTP, IMAP, IRC, NNTP, POP3, SIP, SMTP, SNMP, SSH, Telnet, BitTorrent, … |
| Transport | DCCP, SCTP, TCP, RTP, UDP, IL, RUDP, … |
| Network | IPv4, IPv6, … |
| Data link | Ethernet, Wi-Fi, Token ring, FDDI, PPP, … |
| Physical | RS-232, EIA-422, RS-449, EIA-485, 10BASE2, 10BASE-T, … |
Examples
- AFP, Appletalk Filing Protocol
- AIM, AOL Instant Messenger Protocol
- APPC, Advanced Program-to-Program Communication
- BitTorrent
- CFDP, Coherent File Distribution Protocol
- DHCP, Dynamic Host Configuration Protocol
- FTAM, File Transfer Access and Management
- FTP, File Transfer Protocol
- Gopher, Gopher protocol
- HTTP, HyperText Transfer Protocol
- IMAP, Internet Message Access Protocol
- IRC, Internet Relay Chat
- iTMS, iTunes Music Store Protocol
- LDAP, Lightweight Directory Access Protocol
- Modbus
- NNTP, Network News Transfer Protocol
- POP3, Post Office Protocol
- SIP, Session Initiation Protocol
- SMTP, Simple Mail Transfer Protocol
- SNMP Simple Network Management Protocol
- SSH, Secure Shell
- TELNET, TELEphone NETwork
- TFTP, Trivial File Transfer Protocol
- TSP, Time Stamp Protocol
- X.400
- X.500
- XMPP, Extensible Messaging and Presence Protocol
