A protocol is a structure in which data is transmitted between two devices. The structure may vary from a set of devices to another set of devices for the data that is transmitted among them. The following issues are directly associated with the protocol between the devices:
➢ What is the procedure that is to be followed to check the errors in the message?
➢ Is the message going to be compressed during transmission? If yes, what is the method that will be adopted?
➢ How does the receiver know that the message is received completely? (That is, the way to find the end of the message.)
➢ How will the receiver acknowledge the sender that the former has received the message? There are a number of protocols in existence.
The protocols that are to be used are totally dependent on the computers that communicate with each other. In this research, there is a focus on only those protocols that are related to the Internet. There are some protocols which transmit the message/data in the form of packets. The message is divided into packets and these packets are then transmitted from the source to the destination. It is not essential that all the packets travel in the form of a convoy from the source to the destination. Each packet may follow its own route from source to the destination. Once, all the packets are received at the destination, the computer will recompile them into the original message.
Any computer that is connected to the Internet has an address. This address is called an IP address. The IP address is made up of 32 bits. It is denoted by four numbers which are separated by periods. A modem is a device that converts digital data to analog form and analog data to digital form.
TCP/IP: Transmission Control Protocol / Internet Protocol:
TCP/IP stands for Transmission Control Protocol/ Internet Protocol. TCP/IP is not a single protocol but is a set of communication protocols that are used to connect the computers that have data to be transmitted over the Internet. Every machine on Internet transmits data. The client machine transmits queries, servers transmit answers. ❖ TCP A TCP connects the destination and source
A TCP connects the destination and source machines on the Internet. This enables both of them to transmit data between each other. The following are the advantages of TCP:
➢ The message is definitely delivered from the source to the destination.
➢ The packets that make up the message are delivered in the same order to the destination as they are transmitted from the source.
This protocol specifies the structure of the packet. That is the place from where the data starts and where it ends inside the packet. Also, it is this protocol which specifies the position of this packet in the set of packets that form the message so that it can be used during the time of recompilation at the destination. The packets are also called datagrams. IP also specifies the addressing scheme for the packets.
The packets are also called datagrams. IP also specifies the addressing scheme for the packets. Several versions of IP are released since it’s inception. The current version is IPv6. When a computer (source) wants to send message/data to another computer (destination), then the source specifies the address of the destination and confirms that the message/data is to be sent. Then, IP comes into action. It splits the data into packets and specifies the addressing scheme. Once IP has done its job, TCP comes into action. It establishes a connection between the source and destination so that the packets can be transmitted between them. It is not necessary that only source sends data to the destination. Once the communication starts, the destination is also permitted to communicate with the source over the same connection. TCP also ensures that all the datagrams (packets) reach the destination and vice-versa. Also, it ensures that the order of receipt of packets at source/destination is the same as they are transmitted by the source/destinations.
So, it is both TCP and IP which lead to communication between the source and destination. TCP/IP is the default standard for Internet based communication. Almost, all the network operating systems support them. That is the primary reason for Internet being a network of machines that are based on different operating systems. Needless to say, TCP/IP uses packet switching technology. The alternative is circuit switching technology in which the message/data travels along a fixed line from the source to destination and the destination receives data in the same order in which it is sent from the source.
SLIP: Serial Line Internet Protocol:
SLIP stands for Serial Line Internet Protocol. This is a protocol that is used to connect to the Internet through telephone lines. So, if the Internet connection is a Dial-up connection, this protocol can be used. But, SLIP is an older protocol and very few Internet service providers are using it. It was developed when the speed of connection was around 2kbps. SLIP transmits data over serial lines. That is, data is transmitted one bit at a time which is time-consuming.
PPP: Point to Point Protocol:
PPP stands for Point to Point Protocol. This is another protocol that is used to connect to the Internet through telephone lines. This is the protocol that is being used by most of the ISPs (Internet Service Providers) for dial-up access to the Internet. This is a protocol that works comfortably with the speeds that even exceed 64kbps. It supports error detection (That is, any error that creeps in during the transmission of the message between the source/destination can be detected) and data compression. The packets that are generated by TCP/IP are sent by PPP to a server that in turn places these packets on the Internet.
FTP: File Transfer Protocol:
FTP stands for File Transfer Protocol. This is the protocol that is used to upload/download files to/from the Internet. When files are to be exchanged between source/destination, FTP comes into action. FTP uses TCP/IP to enable the transfer of data between source/destination. Whenever a website is to be hosted, web pages are uploaded to the concerned web server. It is the FTP which enables the uploading of files.
HTTP: Hyper Text Transfer Protocol:
HTTP stands for Hyper Text Transfer Protocol. This is the protocol that is used to transfer web pages between a web browser and web server. HTTP does a wide variety of tasks. The way the data/message is to be formatted is specified by HTTP. The way the data/message is to be transmitted is also specified by HTTP. Whenever data is transmitted between a web browser and web server, both the browser and the server need to respond to the commands of each other. The nature of the response is also defined by HTTP6. When we need to go to a particular website, it is the home page which is usually loaded into our browser. So, when we type the website address/URL in the location bar of the browser and press ENTER or click at “go”, it is the HTTP which guides the web server about the web page that is to be sent to the browser in response to the URL.
HTTPS: Secure HTTPS:
HTTPS stands for Secure HTTP. Whenever message/data is to be sent securely, HTTPS is used. It does not mean that whatever data is sent between browser/ server is secure. Only a particular message/data is secure when HTTPS is enabled during its transmission. An analogy of such office, which we otherwise do from our terminal in the office. We can execute commands from the terminal on which TELNET is running on the server without realising the fact that we are away from our office. TELNET enables us to login to our office LAN and does work as we are doing while sitting in our office and accessing the LAN from a terminal which is connected to the LAN.
NNTP: Network News Transfer Protocol:
It stands for Network News Transfer Protocol. USENET is a bulletin board system in the Internet. Anyone who registers with USENET can access the bulletin board, post to it as well as receive the information that is added to the bulletin board through e-mail automatically. NNTP is used to access, post and receive information from the USENET.
WAP: Wireless Application Protocol:
It stands for Wireless Application Protocol. It is used by wireless devices such as mobile phones, PDAs, etc. to access Internet. So, any person having a mobile phone which is WAP enabled can access the websites by connecting to the Internet from his/her mobile phone8.
ICMP: Internet Control Message Protocol:
It stands for Internet Control Message Protocol. It is an extension of Internet Protocol (IP). Any packet which consists of error messages/control information/ any other information is supported by ICMP. For example, a PING command uses ICMP. PING is used to find the accessibility of an IP address.
IGMP: Internet Group Management Protocol:
It stands for Internet Group Management Protocol. IP multicasting refers to the ability of a server to broadcast a message to a number of destinations at a time. IGMP is the standard for IP multicasting over the Internet. IGMP enables a single set of packets to be transmitted from a source to a number of destinations. Conventionally, when a message is addressed to more than one recipient, one set of packets is transmitted to each recipient separately. So, if we address ten recipients, ten sets of packets are transmitted from the source to all the ten recipients at a rate of one set of packets per recipient. But, IGMP enables just one set of packets to reach all the ten recipients.
IMAP: Internet Message Access Protocol:
It stands for Internet Message Access Protocol. It is used to retrieve e-mail messages. The latest version of IMAP is IMAPv4.0. The latest version has some additional features such as enabling the user to retrieve only those e-mail messages which consist of specific keyword(s).
- Original Reference Article: Begum, S. S. (n.d.). A study on the usage of internet resources among engineering students in Madurai district. Alagappa University, Department of Library and Information Science.