The OSI Application Layer
By Stephen Bucaro
The Application layer, layer seven of the OSI model, provides the interface between
applications and the Network Operating System (NOS). The Application layer provides
network services and applications such as HTTP (Hypertext Transfer Protocol), FTP (File
Transfer Protocol), TELNET, SNMP (Simple Netwrok Management Protocol) and SMTP (Simple
Mail Transport Protocol).
When you think of the Application layer, don't think in terms of applications, but
rather protocols. For example there are several different FTP applications that use
the FTP protocol at the Application layer.
More Networking Protocols and Standards:
• Internet Protocol versions IPv4, IPv5 and IPv6
• Classless IP Addressing
• Video - Transport Layer (Layer 4) of OSI Networking Model
• X.25 and Frame Relay Overview
• IEEE 802.11 Wireless Modulation Methods
• WAN Network Protocols - DSL, SONET, HDLC, DWDM, DLSW+
• What Are Private IP Addresses?
• What is PPP, PPPoA and PPPoE?
• Shortest Path Bridging (SPB) Protocol
• Basic TCP/IP Networking