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.
The application layer of the four layer and five layer TCP/IP models corresponds to the application layer, the presentation layer and session layer in the seven layer OSI model.
Examples
- 9P, Plan 9 from Bell Labs distributed file system protocol
- AFP, Apple Filing Protocol
- APPC, Advanced Program-to-Program Communication
- AMQP, Advanced Message Queuing Protocol
- Basenet
- BitTorrent
- Atom Publishing Protocol
- BOOTP, Bootstrap Protocol
- CFDP, Coherent File Distribution Protocol
- DDS, Data Distribution Service
- DHCP, Dynamic Host Configuration Protocol
- DeviceNet
- DNS, Domain Name System (Service) Protocol
- eDonkey
- ENRP, Endpoint Handlespace Redundancy Protocol
- FastTrack (KaZaa, Grokster, iMesh)
- Finger, User Information Protocol
- Freenet
- FTAM, File Transfer Access and Management
- FTP, File Transfer Protocol
- Gopher, Gopher protocol
- HL7, Health Level Seven
- HTTP, HyperText Transfer Protocol
- H.323, Packet-Based Multimedia Communications System
- IMAP, IMAP4, Internet Message Access Protocol (version 4)
- IRCP, Internet Relay Chat Protocol
- LDAP, Lightweight Directory Access Protocol
- LPD, Line Printer Daemon Protocol
- MIME (S-MIME), Multipurpose Internet Mail Extensions and Secure MIME
- Modbus
- Netconf
- NFS, Network File System
- NIS, Network Information Service
- NNTP, Network News Transfer Protocol
- NTCIP, National Transportation Communications for Intelligent Transportation System Protocol
- NTP, Network Time Protocol
- OSCAR, AOL Instant Messenger Protocol
- PNRP, Peer Name Resolution Protocol
- POP, POP3, Post Office Protocol (version 3)
- Rlogin, Remote Login in UNIX Systems
- RTPS, Real Time Publish Subscribe
- RTSP, Real Time Streaming Protocol
- SAP, Session Announcement Protocol
- SDP, Session Description Protocol
- SIP, Session Initiation Protocol
- SLP, Service Location Protocol
- SMB, Server Message Block
- SMTP, Simple Mail Transfer Protocol
- SNMP Simple Network Management Protocol
- SNTP, Simple Network Time Protocol
- RDP, Remote Desktop Protocol
- SSH, Secure Shell
- TCAP, Transaction Capabilities Application Part
- TDS, Tabular Data Stream
- TELNET, Terminal Emulation Protocol of TCP/IP
- TFTP, Trivial File Transfer Protocol
- TSP, Time Stamp Protocol
- VTP, Virtual Terminal Protocol
- Waka (protocol), an HTTP replacement protocol
- Whois (and RWhois), Remote Directory Access Protocol
- WebDAV
- X.400, Message Handling Service Protocol
- X.500, Directory Access Protocol (DAP)
- XMPP, Extensible Messaging and Presence Protocol