Define remote and Web system protocols

A set of network protocol layers that work together to provide the services on a communications network is called a protocol stack. The stack is a conceptual representation of the role each protocol plays relative to another protocol. Each layer in a protocol has a function and represents a step in a hierarchical structure. The figure below shows the TCP/IP protocol stack, with the remote access protocols at the top of the hierarchy. Remote access protocols allow users to connect to another computer via distant or local networks and access files or data. The following diagram displays the various protocol layers:

The Internet and the World Wide Web are based on TCP/IP. The term "TCP/IP" refers to not only the TCP (transmission control protocol) and IP (Internet protocol), but also includes other protocols, applications, and even the network medium. These protocols include UDP, ARP, and ICMP. These applications include telnet, FTP, Secure Shell, NFS,Web browsers and servers, and the many items collectively called the Web services. This chapter is an encyclopedic survey of these topics starting from the seven-layer OSI model to recent improvements in the implementations of the protocol stack and firewalls. A computer system communicates with another system by sending a stream of bytes. A byte is a sequence of 8 bits. A checksum is the arithmetic sum of a sequence of numbers used to detect errors that may have altered some of the numbers in the sequence. The communication is actually between a process running on one system with one running on the other system. The two processes communicate information in a pre-agreed form known as protocol. That is, the two processes agree on the meaning of specific byte values occurring in specific positions in the stream. This chapter describes the core protocols known as IP and TCP, and a few application protocols based on these. The details of IP and TCP are not directly experienced by the ordinary user unless a network sniffer is used. Nevertheless, it is crucial to understand these before attempting to understand the application protocols. In each protocol, there is a stream of bytes known as a frame, a datagram, a packet or a segment depending on the "level".

Specifies the format of packets, or datagrams, and the addressing scheme they use.

1. UDP: User Datagram Protocol establishes a more efficient way to send and receive information. It is used mostly for streaming music or video, where real time performance is important.
2. TCP: Transmission Control Protocol establishes a virtual connection between a destination and a source.
3. HTTP: Hypertext Transfer Protocol transfers information from World Wide Web servers to browsers.
4. FTP: FTP is used to send files over the Internet.

Higher level protocols and custom protocols meet discrete connection requirements.

Point-to-Point Protocol (PPP), Point-to Point Tunneling Protocol (PPTP) and Serial Line Protocol (SLIP) are the three most widely used communication protocols. The table below lists their key features and the differences between them:

Protocol	Characteristics
(PPP) Point-to-Point Protocol	Provides dial-up access over serial lines and automatic login and configuration negotiation
(PPTP) Point-to-Point Tunneling Protocol	1.Allows data in TCP/IP format to be transmitted over a non-TCP/IP network Can be used to set up a VPN virtual private network, but is only available on networks served by Windows 2008 or later
(SLIP) Serial Line Internet Protocol	1. Provides access to the Internet or dial-up access between two LANs. 2. Older and not as well-designed as PPP.

In the next lesson, the network requirements necessary to meet business goals for a Web site development project will be discussed.

Click the quiz link below to check your learning of protocols and addresses.
Protocols Addresses - Quiz