What is communication protocol?
A communication protocol is a standardized set of rules and conventions that dictate how data is exchanged between devices or systems in a network. It outlines the data format, the transmission method, error detection and correction procedures, and other aspects necessary for reliable communication. These protocols ensure that devices can understand each other and communicate effectively, facilitating the seamless exchange of information across networks.
What are common communication protocols?
The most popular networking communication protocols are:
TCP/IP (Transmission Control Protocol/Internet Protocol): A foundational protocol suite for internet communication, responsible for data transmission and routing. Examples include HTTP for web browsing and SMTP for email.
HTTP (Hypertext Transfer Protocol): Used for transferring web pages and related files over the internet. It governs the request-response cycle between web clients and servers. It's a bit old and obsolete nowadays.
HTTP/3 (Hypertext Transfer Protocol version 3) is the latest version of the Hypertext Transfer Protocol (HTTP), which is the foundational protocol used for data communication on the World Wide Web. It represents a significant evolution over its predecessors (HTTP/1.1 and HTTP/2
HTTPS (Hypertext Transfer Protocol Secure): A secure version of HTTP that encrypts data during transmission, commonly used for secure transactions on the web, such as online banking and e-commerce. Modern web standard protocol.
SSL/TSL(Secure Socket Layer/Transport Layer Security) cryptographic protocol that provides secure communication over the Internet. Commonly used to secure sensitive data transmission, such as login credentials, credit card information, and other personal information, between a client (like a web browser) and a server.
User Datagram Protocol (UDP) is a network protocol that operates at the transport layer of the Internet Protocol (IP) suite. It's designed to provide a lightweight and low-overhead method for sending datagrams, or chunks of data, across a network.
The Internet Control Message Protocol (ICMP) is a network layer protocol used primarily for error messages and operational information in IP networks. It helps diagnose network issues by sending messages about issues like unreachable destinations, network congestion, or packet loss. ICMP is commonly used in tools like "ping" and "traceroute" to test connectivity and measure response times. Unlike TCP or UDP, ICMP isn't used for data transmission; instead, it supports network health by notifying sources about potential network issues.
QUIC (Quick UDP Internet Connections) is a transport layer network protocol developed by Google. It aims to improve the performance of connection-oriented web applications by reducing latency and providing better congestion control.
FTP (File Transfer Protocol): Facilitates the transfer of files between a client and a server on a network. It allows users to upload, download, and manage files remotely.
SMTP (Simple Mail Transfer Protocol) Used for sending email messages between servers. It defines how email messages are transmitted and delivered over the internet.
SNMP (Simple Network Management Protocol) widely used for monitoring and managing network devices such as routers, switches, servers, and printers. SNMP enables network administrators to collect information about web devices and monitor their performance, configuration, and health.
XMPP (Extensible Messaging and Presence Protocol) It’s an open-source protocol for instant messaging (IM), presence information, and real-time applications. XMPP is part of the Jabber technologies and XMPP.org family
POP3 (Post Office Protocol version 3) used for retrieving email messages from a server. It allows users to download emails to their local devices for offline access.
IMAP (Internet Message Access Protocol): Similar to POP3, IMAP is used for accessing and managing email messages stored on a server. It enables users to organize, search, and synchronize emails across multiple devices.
DNS (Domain Name System): Converts domain names into IP addresses, allowing users to access websites using human-readable addresses. DNS is essential for navigating the internet.
SSH (Secure Shell): A protocol for secure remote access to computers or servers over a network. It provides encrypted communication channels for secure command-line, file transfer, and tunneling services.
Bluetooth: A wireless communication protocol used for short-range data exchange between electronic devices. Bluetooth enables devices like smartphones, laptops, and IoT devices to connect and communicate with each other for tasks such as file sharing, audio streaming, and device control.
NTP (Network Time Protocol): It's is a networking protocol used to synchronize the clocks of computers over a network to a precise time source.
SysLog it's old web standard for logging system messages in computer networks. It enables network devices, operating systems, and applications to generate messages about their activities, errors, and statuses and send them to a centralized logging server or collector.
PPTP (Point-to-Point Tunneling Protocol). It's a method for implementing virtual private networks (VPNs) that was developed by Microsoft in conjunction with other technology companies. PPTP allows for the creation of a secure and encrypted connection (tunnel) between a remote user and a private network, typically over the internet.
IPsec (Internet Protocol Security) is a set of standards that provides security for Internet Protocol (IP) communications. It ensures data confidentiality, integrity, and authenticity between participating peers (e.g., hosts, routers, gateways) by encrypting IP packets. IPsec can be used to secure communication across a Virtual Private Network (VPN), site-to-site connections, or even between a client and a server.
UART (Universal Asynchronous Receiver/Transmitter) is a serial communication protocol used between devices. Unlike synchronous methods that rely on a clock signal, UART uses a predefined baud rate to synchronize communication. Data is transmitted one bit at a time, starting with a start bit, followed by data bits (typically 7 or 8 per character), an optional parity bit for error-checking, and stop bits. Both devices must use the same baud rate for accurate data transfer.
I2C (Inter-Integrated Circuit) is a synchronous serial communication standard used for connecting peripherals to a microcontroller or system-on-chip. It allows multiple devices to communicate over a single bus, using two wires for data (SDA - serial data line) and clock (SCL - serial clock line). Devices on the bus are addressed individually, enabling both master-slave and multi-master configurations. I2C supports communication speeds ranging from a few hundred bits per second (Standard Mode) to several megabits per second (High-Speed Mode), with devices operating at different speeds easily accommodated through clock stretching.
H.323 is a set of standards from the International Telecommunication Union (ITU) for multimedia communications over packet-switched networks, such as the Internet. It covers standards for audio, video, and data conferencing, enabling interoperability between different vendors' equipment. H.323 includes components like terminals, gateways, gatekeepers, and multipoint control units (MCUs) to support services like voice over IP (VoIP) and video conferencing.
HLS (HTTP Live Streaming) developed by Apple for streaming audio and video over the internet. It breaks streams into small, HTTP-based file segments and uses playlist files (M3U8) to direct the player to the segments. HLS supports adaptive bitrate streaming, adjusting the stream quality based on network conditions to ensure smooth playback. It is widely used for its reliability and compatibility across various devices and platforms like Netflix & Instagram.
WebRTC (Web Real-Time Communication) an open-source protocol that enables real-time communication capabilities directly in web browsers and mobile apps. It provides APIs allowing developers to build applications with real-time audio, video, and data streaming capabilities. Used by Google Meet, Microsoft Teams, and Zoom.
CoAP (The Constrained Application Protocol) is a specialized web transfer standard designed for use in constrained nodes and networks, such as those in IoT environments. It operates over UDP and supports methods like GET, POST, PUT, and DELETE. CoAP is optimized for low-power, low-memory devices, enabling efficient machine-to-machine communication with mechanisms for reliability and simple RESTful interaction.
Session Description Protocol (SDP) is used to describe multimedia communication sessions. In WebRTC, SDP is used during the signaling process to exchange information about media capabilities (codecs, formats, network information) between peers.
STUN (Session Traversal Utilities for NAT) network protocol used to facilitate communication between devices behind Network Address Translators (NATs) and firewalls. NATs are commonly used in home and office networks to allow multiple devices to share a single public IP address. However, NATs can complicate direct communication between devices because they often mask the internal IP addresses.
DTLS (Datagram Transport Layer Security) protocol designed to provide security for datagram-based applications, such as those using the User Datagram Protocol (UDP). DTLS is based on the Transport Layer Security (TLS) protocol, which is used to secure communication over connection-oriented protocols like TCP.
RTP (Real-time Transport Protocol) It's a network protocol used for delivering audio and video over IP networks, such as the internet. RTP is designed to provide end-to-end delivery services for real-time data, which is crucial for applications like video conferencing, voice over IP (VoIP), and live streaming.
[obsolete] RTMP (Real-Time Messaging Protocol) is a proprietary, TCP-based protocol for streaming live video, audio, and data to Flash-enabled devices. Originally developed by Macromedia and later acquired by Adobe. RTMP is considered obsolete due to the decline of Flash and the rise of newer streaming protocols based on HTTP like HLS (HTTP Live Streaming) and DASH (Dynamic Adaptive Streaming over HTTP).
These protocols play crucial roles in aspects of modern communication, from web browsing and email exchange to file transfer and device connectivity.
Communication protocols classification
Communication protocols can be classified based on various criteria such as their application layer, the type of service they provide, or their operational layers in the OSI (Open Systems Interconnection) model.
Based on Application Layer
Email Protocols
SMTP (Simple Mail Transfer Protocol) Used for sending emails.
IMAP (Internet Message Access Protocol) for retrieving emails.
POP3 (Post Office Protocol 3 for retrieving emails.
Web Protocols
HTTP (Hypertext Transfer Protocol) Used for accessing web pages.
HTTPS (Hypertext Transfer Protocol Secure) Secure version of HTTP.
ICMP (The Internet Control Message Protocol) for error messages and operational updates
File Transfer Protocols
FTP (File Transfer Protocol) & SFTP (Secured File Transfer Protocol) Used for transferring files
TFTP (Trivial File Transfer Protocol) Simplified version of FTP.
Remote Access Protocols
SSH (Secure Shell) Secure method for remote login.
Telnet Unsecured method for remote login.
Streaming Protocols
HLS (HTTP Live Streaming) Adaptive bitrate streaming protocol by Apple.
DASH (Dynamic Adaptive Streaming over HTTP) International standard for adaptive streaming.
RTMP (Real-Time Messaging Protocol) Used for live streaming.
RTSP (Real-Time Streaming Protocol) Used for establishing and controlling media sessions.
WebRTC (Web Real-Time Communication) Effective peer-to-peer communication for video and audio.
SRT (Secure Reliable Transport) Optimized for streaming over unpredictable networks
Based on Transport Layer
TCP/IP Suite
TCP (Transmission Control Protocol): Connection-oriented protocol
UDP (User Datagram Protocol) Connectionless protocol
IP (Internet Protocol) Handles addressing and routing
Connection-Oriented Protocols
TCP Ensures reliable and ordered delivery of data
SCTP (Stream Control Transmission Protocol) Supports multi-homing and multi-streaming
Connectionless Protocols
UDP Provides low-latency and loss-tolerating connections.
Based on Network Layer
IP Protocols
IPv4 (Internet Protocol version 4) The fourth version of the IP
IPv6 (Internet Protocol version 6) Successor to IPv4 with a larger address space.
Routing Protocols
BGP (Border Gateway Protocol) Manages how packets are routed across the internet.
OSPF (Open Shortest Path First) Routing within larger autonomous systems
RIP (Routing Information Protocol) Simplified routing for small networks.
Based on Data Link Layer
Ethernet Protocols
Ethernet Standard for wired local area networks
Wi-Fi (Wireless Fidelity) radio waves tech that allows devices to connect to internet wirelessly within a local area network (LAN)
Point-to-Point Protocols
PPP (Point-to-Point Protocol) Used for direct communication between two network nodes
HDLC (High-Level Data Link Control) Bit-oriented code-transparent synchronous data link layer protocol
Based on Presentation and Session Layers
Session Protocols
NetBIOS (Network Basic Input/Output System) Provides services related to the session layer of the OSI model.
PPTP (Point-to-Point Tunneling Protocol) For implementing virtual private networks.
Presentation Protocols
TLS (Transport Layer Security) Provides secure communication.
SSL (Secure Sockets Layer) Predecessor to TLS for secure communications.
Specialized Protocols
VoIP Protocols
SIP (Session Initiation Protocol) Initiates, maintains, and terminates real-time sessions.
H.323 Set of protocols for voice, video, and data conferencing.
IoT Protocols
MQTT (Message Queuing Telemetry Transport): Lightweight protocol for small sensors and mobile devices.
CoAP (Constrained Application Protocol): Specialized for IoT device control with limited resources.
