Application Layer 7

It is employed in software packages which implement client-server software. When an application on one computer starts communicating with another computer, then the Application layer is used. The header contains parameters that are agreed between applications. This header is often only sent at the beginning of an application operation. Examples of services within the application layer include:

• FTP
• DNS
• SNMP
• SMTP gateways
• Web browser
• Network File System (NFS)
• Telnet and Remote Login (rlogin)
• X.400
• FTAM
• Database software
• Print Server Software