Page 32 - M. Abrahim Thesis

Chapter (2) Network Fundamental and Layered Network Architecture

present version of TCP/IP is old. Internet Protocol Version 4 (IPv4) was standardized in
September 1981. In 1992 the standardization of a new generation of Internet Protocol (IP), often
called IPng, was supported by the Internet Engineering Task Force (IETF). IPng is now called
Internet Protocol Version 6 (IPv6).
Application Layer

TCP/IP was designed with a high-level protocol layer that includes OSI session,
presentation, and application layer details. The application layer, shown in Figure 2-8, handles
high-level protocols and issues of representation, encoding, and dialog control.

Figure 2-8 shown a TCP/IP Application Layer Protocol

The TCP/IP protocol suite combines all application-related issues into one layer and
ensures that this data is properly packaged for the next layer.

TCP/IP includes not only Internet and transport layer specifications (such as IP and TCP)
but also specifications for common applications.
TCP/IP has protocols to support file transfer, e-mail, and remote login, including the
following applications:

■ Hypertext Transfer Protocol (HTTP)

The underlying protocol used by the World Wide Web. HTTP defines how messages are
formatted and transmitted and what actions web servers and browsers should take in response
to various commands.

■ Trivial File Transfer Protocol (TFTP)

A connectionless service that uses User Datagram Protocol (UDP). TFTP is used on the
router to transfer configuration files and Cisco IOS images and to transfer files between systems

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