The application layer contains all protocols and methods that fall into the realm of process-to-process communications across an Internet Protocol (IP) network. Application layer methods use the underlying transport layer protocols to establish host-to-host connections.
The Internet protocol suite (TCP/IP) and the Open Systems Interconnection model (OSI model) of computer networking each specify a group of protocols and methods identified by the name application layer.
The following protocols are part of the application layer of the Internet protocol suite.
- Remote login category - Telnet
- File transfer category - FTP, TFTP
- Electronic mail category - SMTP, IMAP, POP
- Support services category - DNS, RARP, BOOTP, SNMP
It covers the following topics -