An Introduction To Communication Protocols
The Internet and the World Wide Web are not controlled or regulated by anyone. In such a largely unregulated digital environment,?how are the wide variety of connected devices able to communicate with each other? More specifically,
Unlike in the kitchen where water streams down the faucet as soon as one turns it on, in a computer network, data cannot freely flow all the time. Meaningful data flow can occur among networked devices only if transmitted data is sequenced and synchronized in great detail. And this is where communications protocols play a pivotal role.
In this article, we will discuss communication protocols, their different types, and their role in computer networking.
WHAT IS A COMMUNICATION PROTOCOL?
Communication protocols are sets of formal rules that describe how digital messages must be formatted. They are vital in networking and telecommunication systems because they bring uniformity in the sending and receiving of digital messages. So, communication protocols are necessary for the exchange of messages in or between computing systems.
Before networked devices can share information, they need to agree on various aspects of communication. And the communication protocols define these rules that govern data transmission. The communication protocols are usually constructed based on the Open System Interconnect (OSI) model with the communication functions divided into protocol layers.
Communication protocols are implemented in hardware and software and usually cover authentication, error detection, correction, and signaling. Additionally, communication protocols may describe the syntax, semantics, and synchronization of the communications. The following are common properties that the protocols include:
WHAT ARE THE TYPES OF COMMUNICATION PROTOCOLS?
Although there are thousands of network protocols, all of them can be classified into the following three:
1. COMMUNICATION PROTOCOLS
As mentioned above communication protocols are sets of rules that facilitate communication between different network devices. These protocols are used for a variety of purposes such as transferring files, automating processes, text-based communications, accessing the Internet, etc.
Common communication protocols include:
2. NETWORK MANAGEMENT PROTOCOLS
Network management protocols provide the rules for effectively operating a computer network. These protocols define the policies and procedures for monitoring and managing a network to ensure stable communication and performance.
Network management protocols provide vital information such as host availability, packet loss, the health of the connection, etc. Network operators then use this information to troubleshoot network connectivity issues and improve network performance .
Network management protocols apply to all network devices such as routers, switches , servers, computers, etc., and are responsible for establishing and maintaining stable connections between the network devices. They also help network administrators identify network errors, evaluate the quality of the network connection, and determine how to fix the network issues .
3. SECURITY PROTOCOLS
Security protocols are communication protocols that use cryptographic mechanisms to ensure that the network and the data sent over it are protected from unauthorized users. These protocols define the sequence and formats of digital messages including cryptographic elements exchanged between network devices.
Security protocols are instrumental in providing security services such as confidentiality, authentication, and integrity for data transmitted over the network. To achieve this security protocols fulfill the following functions:
3. WHAT IS TRANSMISSION CONTROL PROTOCOL/INTERNET PROTOCOL (TCP/IP)
The Transmission Control Protocol/Internet Protocol (TCP/IP) is made up of a suite of non-proprietary protocols used to interconnect devices on the Internet as well as on private networks. The TCP/IP protocol suite defines how applications can create channels of communication over the network. It also governs how digital messages are assembled into packets, addressed, transmitted, routed, and reassembled at the destination.
TCP and IP are the main protocols in this suite or collection of protocols. TCP deals with how applications create communication channels, transmit, and receive messages. While IP deals with addressing and routing the messages. TCP/IP makes networks reliable with the ability to recover automatically from device failures, so it requires little to no central management.
The architecture of TCP/IP is similar to that of the OSI model and consists of layers. The four layers of TCP/IP are:
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In the newer version of the TCP/IP model, the link layer has been split into the data link layer and the physical layer. Additionally, the internet layer has been renamed as the network layer. So the newer model of TCP/IP is as follows:
When a network device sends data to another device, a bit of information is added by each layer starting from the application layer and moving down. When the data reaches the physical layer, the data is transmitted to the receiving device.
For example, say you start with application data. It is first passed down to the next layer, i.e. the transport layer, where a TCP header containing the source and destination port numbers, sequence numbers, etc. are added. The data then moves to the network layer, where the IP header, which contains the source and destination IP addresses, is added. Then it is passed to the data link layer, where a header, as well as a trailer, are added. The header contains the source and destination MAC addresses and the trailer contains some error-checking information that the destination device can use to ensure that the data has been received correctly. After that, the data is sent to the physical layer, which physically transmits the data to the destination.
This process of sequentially adding data is called encapsulation. At each stage of encapsulation, the data has a different name. In the transport layer, after the relevant information has been added, the data is called a segment. After network layer information is added, it is called a packet. And once the data link information is added, it is called a frame.
After the transmitted data has been received, the receiving device decapsulates the data. The decapsulation occurs in the reverse order, starting from the MAC address in the frame. It is processed further only if the device MAC address matches the destination MAC address in the frame. Then the device checks the IP information of the packet, which will be processed further only if the IP address matches the destination information in the packet. After this, the transport information is read and the application data is sent to the receiving application.
4. WHAT ARE SOME COMMON NETWORK PROTOCOLS?
Earlier in this blog post, we already mentioned the Internet Protocol (IP) and the File Transfer Protocols (FTP), which are probably the most common network protocols. In addition to them, here are a few more commonly used protocols:
1. HYPERTEXT TRANSFER PROTOCOL (HTTP)
The World Wide Web functions based on communication between web clients, i.e. browsers, and web servers in the cloud. This communication between client and server happens through the HTTP request/response circle. HTTP is an application layer protocol that is sent over a TCP connection.
The HTTP protocol fetches resources such as HyperText Markup Language (HTML) documents, functioning as the foundation of data exchange on the web. In addition to fetching HTML documents, it can also fetch images and videos or post content to servers.
Hypertext transfer protocol secure (HTTPS) is the secure version of HTTP, which is encrypted in order to increase the security of data transfer.
2. SECURE SOCKET SHELL (SSH)
Secure Socket Shell (SSH) is a network protocol that enables users and system administrators to access network devices over an unsecured network. SSH uses a strong password and/or a cryptographic key pair for authentication.
SSH thus allows users to remotely connect to computers or applications and execute commands in a secure way. The SSH protocol is typically used by administrators for executing system management tasks.
3. USER DATAGRAM PROTOCOL (UDP)
User Datagram Protocol (UDP) is a communication protocol that facilitates data transfer between network devices. Similar to TCP, UDP also operates in the transport layer and serves as an alternative to TCP where transmissions are time-sensitive and reliability is not as important.
UDP does not formally establish a connection before starting the data transfer, thus speeding up the data transfer. However, this can cause loss of packets. UDP finds use in voice and video communications since they are time-sensitive and designed to handle some amount of packet loss.
For example, UDP is used for real-time communication such as Voice over Internet Protocol (VoIP) telephony. In this case, UDP is preferred over TCP because some loss in voice quality is preferable to heavily delayed transmission.
CONCLUSION
There are thousands of communication protocols used all around us and computer networking could not exist without them. For example, right now you are using the Internet Protocol Suite (TCP/IP) and the Hypertext Transfer Protocol (HTTP) that make it possible for you to connect to the Internet and access the World Wide Web.
Understanding communication protocols is essential for anyone who wants to understand computer networks. This understanding enables network administrators to be more efficient at troubleshooting network issues and providing effective network administration and security.
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