Application layer
| 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 (7) 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.
| Application layer | HTTP, HTTPS, SMTP, FTP, UUCP, NNTP, SSH, IRC, SNMP, SIP, RTP, Telnet ,... |
| Transport layer | TCP, UDP, SCTP, DCCP, ... |
| Network layer | IPv4, IPv6, ICMP, ARP, IGMP, ... |
| Data link layer | Ethernet, Wi-Fi, Token ring, FDDI, PPP, ... |
| Physical layer | RS-232, EIA-422, RS-449, EIA-485... |
Examples
- HTTP
- SMTP
- SNMP
- FTP
- TFTP (Trivial File Transfer Protocol)
- NNTP
- gopher
- XMPP
- Telnet
- FTAM
- APPC
- X.400
- SSH
- X.500
- IRC
- AFP
- Lightweight Directory Access Protocol (LDAP)
- SIP
- ITMS
- AIM
- Modbus