Network Protocols

Network protocols are a set of rules responsible for communication between various devices on a network. These protocols define the necessary guidelines and regulations for transmitting and receiving data to ensure efficient and reliable communication.

A network protocol is a set of rules that govern data communication between different devices on a network. It determines what is to be communicated, how it is to be communicated, and when it is to be communicated. It enables connected devices to communicate with each other regardless of internal and structural differences.

Understanding network protocols is essential to comprehend how devices communicate over a network. The Open Systems Interconnection (OSI) model, the most widely used model, illustrates how computer systems interact over a network. The communication mechanism between two network devices is represented by seven distinct layers in the OSI model.

Each layer in the OSI model operates based on different network protocols. Each layer has one or more protocols for network communication. For example, the Internet Protocol (IP) routes data by controlling the source and destination addresses of data packets, enabling connections across networks. It is known as a network layer protocol.

Types of Network Protocols

In most cases, communication over a network such as the Internet uses the OSI model. The OSI model consists of seven layers in total. Secure connections, network management, and network communication are the three key functions performed by network protocols. The purpose of protocols is to connect different devices. Protocols are generally classified into three main categories:

1. Network Communication

2. Network Management

3. Network Security

Network Communication

Communication protocols are fundamental building blocks of network operation. They are so essential that having a computer network without them is impossible. These protocols formally define the rules and formats for data transfer. They address issues such as syntax, semantics, detection, synchronization, and authentication. Below are some network communication protocols:

Hypertext Transfer Protocol (HTTP)

A layer 7 protocol designed to transfer hypertext between two or more system. HTTP operates on a client-server model, and most web-based data sharing is done using HTTP.

Working Principle of HTTP Protocol (Source: geekflare.com)

Transmission Control Protocol (TCP)

TCP organizes reliable stream delivery using sequential acknowledgments. It is a connection-oriented protocol, meaning it establishes a connection between applications before any data is sent. It is used for communication over a network and has numerous applications such as email, FTP, media streaming, and others.

Working Principle of TCP Protocol (Source: geekflare.com)

User Datagram Protocol (UDP)

A connectionless protocol that provides a basic but unreliable service. It does not add flow control, reliability, or error recovery functions. UDP is functional in situations where reliability is not required. It is used when faster transmission is desired, such as for multicast and broadcast connections.

Working Principle of UDP Protocol (Source: geekflare.com)

Border Gateway Protocol (BGP)

BGP is a routing protocol that controls how packets move from router to router within one or more networks operated by a single organization and how they connect to other networks. It links gateway points of a LAN to other LANs and also connects endpoints across different LANs.

Address Resolution Protocol (ARP)

ARP is a protocol that helps map logical addresses to accepted physical addresses on a local network. An ARP cache is used to establish and maintain this mapping between logical and physical addresses.

Internet Protocol (IP)

A protocol used to send data from one host to another over the Internet. It is used for addressing and routing data packets so they can reach their destinations.

Working Principle of IP Protocol (Source: geekflare.com)

Dynamic Host Configuration Protocol (DHCP)

A protocol used for network management to automate the configuration process of devices on IP networks. A DHCP server automatically assigns IP addresses and various other configuration parameters to devices on a network, enabling them to communicate with other IP networks. It also allows devices to use NTP, DNS, or any other TCP or UDP-based protocol service.

Network Management

These protocols help define procedures and policies for monitoring, maintaining, and managing computer networks, and they also facilitate the transmission of these requirements over the network to ensure stable communication. Network management protocols can also be used to resolve connectivity issues between a host and a client.

Internet Control Message Protocol (ICMP)

A layer 3 protocol used by network devices to transmit operational information and error messages. ICMP is used to report congestion, network errors, diagnostic purposes, and timeouts.

Simple Network Management Protocol (SNMP)

A layer 7 protocol used to manage nodes in an IP network. The SNMP protocol has three main components: the SNMP agent, the SNMP manager, and the managed device. The SNMP agent has local information about management details and converts them into a format compatible with the SNMP manager. The manager presents data obtained from SNMP agents to assist in monitoring and resolving network faults and performance issues.

Gopher

A type of file retrieval protocol that provides downloadable files with some descriptions for easy management, retrieval, and searching of files. All files are organized hierarchically on a remote computer. Gopher is an outdated protocol and is rarely used today.

File Transfer Protocol (FTP)

FTP is a client-server protocol used to transfer files to or from a host computer. It allows users to download files, programs, web pages, and other resources available on services.

Working Principle of FTP Protocol (Source: geekflare.com)

Post Office Protocol (POP3)

A protocol used by a local mail client to retrieve email messages from a remote email server over a TCP/IP connection. ISPs also use the POP3 protocol to store and receive emails for their users. Ultimately, these users will use email client software to access their mailboxes on the remote server and download their emails. After the email client downloads the messages, they are typically deleted from the server.

Working Principle of POP3 Protocol (Source: geekflare.com)

Telnet

A protocol that allows a user to connect to and use a remote computer program, designed specifically for remote access. Telnet establishes a connection between a host and a remote endpoint to activate a remote session.

Network Security

These protocols ensure the security of data transmitted over a network. They also determine how the network protects data against attempts by unauthorized individuals to extract or examine it. These protocols prevent any unauthorized device, user, or service from accessing network data. These protocols rely on encryption to secure data.

Secure Sockets Layer (SSL)

A network security protocol primarily used to protect sensitive data and secure internet connections. SSL allows communication both from server to server and from client to server. All data transmitted via SSL is encrypted, preventing unauthorized individuals from accessing it.

Hypertext Transfer Protocol Secure (HTTPS)

The secure version of HTTP. This protocol ensures secure communication between two computers, one sending a request through a browser and the other receiving data from a web server.

Transport Layer Security (TLS)

A security protocol designed to ensure data security and privacy on the Internet. Its functionality includes encryption, verifying data integrity to detect tampering, and authentication. It is commonly used for encrypted communication between servers and web applications, such as when a web browser loads a website. It can also be used to encrypt messages, emails, and VoIP.