TCP/IP

The origins of TCP/IP can be traced back to the innovative efforts of Vint Cerf and Robert Kahn, who in 1973 embarked on a journey to develop a new protocol that would revolutionize the way networks communicated with each other. Their work laid the foundation for what would become the Transmission Control Protocol/Internet Protocol (TCP/IP), a suite of communication protocols designed to interconnect network devices on the internet. This groundbreaking development was aimed at creating a reliable network between two computers, ensuring the seamless exchange of data across diverse systems and platforms.

By the late 1970s, TCP/IP had been meticulously crafted, reflecting the collaborative efforts of researchers led by Cerf and Kahn. Initially developed under the auspices of the United States Department of Defence’s Advanced Research Projects Agency (ARPA) and Stanford University, TCP/IP was intended to forge a robust communication protocol for interconnecting different computer networks. The protocol suite was adopted as the official standard for ARPANET in 1983, marking a significant milestone in its evolution.

Throughout the 1980s and 1990s, TCP/IP witnessed widespread adoption beyond the confines of academic and military institutions. It became the backbone of the burgeoning Internet, facilitating the growth of web browsers, email clients, and other applications reliant on network communication. The introduction of IPv6 in the mid-1990’s was a pivotal moment in the evolution of TCP/IP, primarily addressing the critical issue of IPv4 address exhaustion. IPv4's 32-bit addressing scheme was limited to approximately 4.3 billion unique addresses, a number insufficient for the rapidly expanding internet and its burgeoning number of devices. In contrast, IPv6, with its 128-bit address space, offers a virtually limitless pool of IP addresses, estimated at 340 undecillion (3.4 x 10^38) unique addresses. This vast expansion is crucial for supporting the growth of the Internet of Things (IoT), where every device requires a unique IP address to connect to the internet.

In the subsequent years, TCP/IP continued to evolve, accommodating emerging trends such as mobile devices, cloud computing, and the Internet of Things (IoT). Its role in IoT has been pivotal, ensuring secure end-to-end communication between IoT devices and gateways through encryption protocols like TLS (Transport Layer Security). Furthermore, by utilizing connection-oriented reliable service, no data loss occurs since if a data packet goes missing during transmission, TCP will retransmit the lost packets. This adaptability and resilience have solidified TCP/IP's position as the cornerstone of network communication, underscoring its significance in the digital age.

TCP/IP operates through a layered approach, with each layer responsible for different aspects of the communication process. The model is divided into four layers as follow: 

• Application layer

  Acts as the interface for industrial applications and services, facilitating communication through protocols such as HTTP, FTP, SMTP, DNS, and SNMP. This layer is crucial for enabling end-user software, like web browsers and email clients, to send and receive information, thereby presenting meaningful data to users.

• Transport layer: This layer ensures the reliable or, depending on the protocol used, unreliable delivery of data, managing network traffic between hosts to guarantee complete data transfers. The Transport Layer's responsibilities include ensuring packets arrive in sequence and without error, a task achieved by swapping acknowledgments of data reception and retransmitting lost packets.

• Internet layer

  Charged with the routing and forwarding of data packets between networks. It encompasses the Internet Protocol (IP), which controls the flow and routing of traffic to ensure data is sent speedily and accurately. This layer's function is critical for the movement of packets through the network, ensuring they reach their destination regardless of the path taken.

• Link-Layer

  This layer is responsible for the physical transmission of data over the network medium, handling tasks such as framing, physical addressing, and error detection and correction. Protocols such as Ethernet, Wi-Fi, and PPP operate within this layer, providing reliable data links between nodes and ensuring the integrity of data transmission.

TCP/IP networks supports both cyclic and acyclic communications through their distinct characteristics. TCP, known for its reliability, establishes a connection between source and destination, ensuring data integrity through extensive error-checking mechanisms and flow control. It meticulously tracks the segments being transmitted or received by assigning numbers to every single one of them, thereby guaranteeing the delivery of data to the destination router.

TCP/IP is a connection-oriented protocol that ensures reliable and orderly delivery of data packets across networks. It establishes a connection between the sender and receiver before data transmission and performs error correction and retransmission of lost packets as necessary.

The foundation of TCP/IP's reliability lies in its methodical connection establishment process, which begins with a three-way handshake. This handshake initiates with a SYN packet sent by the sender to express its intent to establish a connection. The receiver responds with a SYN-ACK packet, acknowledging the request and signalling readiness for connection. The handshake concludes with an ACK packet from the sender, confirming the connection setup and marking the commencement of data transmission. Then during packetization, data intended for transmission over a TCP/IP network is divided into smaller units known as packets. Each packet encapsulates a portion of the original data along with essential header information. This header includes source and destination addresses, sequence numbers, and error-checking codes to facilitate accurate delivery and integrity of the data.

To maintain this established connection's reliability, TCP/IP incorporates several mechanisms. Sequence numbers are assigned to each data packet, enabling the receiver to reorder any out-of-sequence packets and identify missing ones. Acknowledgments (ACKs) play a crucial role, as the receiver sends these back to the sender to confirm the successful receipt of packets. In instances where an ACK is not received within a specified timeframe, indicating potential packet loss, the sender retransmits the data.

Flow control further enhances TCP/IP's efficiency by preventing data overload at the receiver's end. Through windowing techniques, the sender adjusts its data transmission rate based on the receiver's current capacity, ensuring that the flow of data remains within manageable bounds. Additionally, error detection and correction mechanisms, such as checksums, are employed to identify and rectify errors in transmitted data packets. Before sending, the sender calculates a checksum value based on the packet's contents. Upon receipt, the receiver performs a similar calculation and compares it to the sender's checksum value. Discrepancies prompt a request for retransmission, ensuring data Integrity. TCP/IP enables data communication across diverse network topologies.

The TCP/IP suite is fundamental in industrial communication, facilitating reliable data transmission across diverse systems. Widely adopted in industrial settings, TCP/IP ensures interoperability among various equipment, control systems, and software platforms, streamlining the integration and operation of complex networks.

IP-based Industrial Ethernet protocols, such as Ethernet/IP, PROFINET, and Modbus TCP, enhance traditional Ethernet's robustness and real-time capabilities, meeting the stringent demands of industrial applications. These protocols support high data transfer speeds, scalable network architectures, and real-time communication, critical for process control and automation.

By leveraging TCP/IP, industrial Ethernet protocols enable seamless connectivity for devices, allowing real-time monitoring, control, and data acquisition. This integration not only optimizes performance but also supports predictive maintenance by analyzing continuous data streams for potential issues.

Incorporating TCP/IP in industrial communication also boosts cybersecurity by applying comprehensive security measures across networks. As Industry 4.0 and IIoT drive the proliferation of connected devices, TCP/IP protocols ensure consistent, secure, and efficient communication, pivotal for the evolution of intelligent, automated industrial environments.

TCP/IP’s significance extends beyond the digital realm, playing a pivotal role in industrial communication systems. The protocol offer’s a myriad of advantages as follows:

• Interoperability

  TCP/IP allows for seamless cross-platform communications among heterogeneous networks, making it an industry-standard model effectively deployed to solve practical networking problems. This adaptability is crucial in a world where different types of computer systems and devices must communicate efficiently and reliably.

• Scalability

  TCP/IP can scale to meet these demands without necessitating a complete overhaul of the existing network infrastructure.

• Enhanced visibility and control over operations

  TCP/IP supports a variety of tasks critical to industrial operations, such as remote login, interactive file transfer, and remote access to a server host's file system.

• Reliability

  Client-server architecture ensures end-to-end data delivery, organizing data so that it can be transmitted between a server and a client while guaranteeing the integrity of the data communicated over the network.

As a leading company in the field of industrial communication, Hilscher offers a broad portfolio of technologies and solutions for networking industrial environments via fieldbus, Real Time Ethernet and IIoT standards.

This includes a wide range of interface solutions for connecting sensors, actuators and controllers to industrial communication networks. The communication controllers of the netX family form the basis for this. The multi-protocol-capable SoCs can be integrated into automation components as required and their extensive chip peripherals enable powerful, efficient and flexible solutions. A protocol change is achieved by simply reloading Hilscher's own netX firmware. Building on this, the company also offers embedded modules and PC cards in all form factors in order to realise the netX communication interface with less integration effort.

Hilscher also offers a comprehensive managed industrial IoT range under the netFIELD brand. This ranges from edge gateways as an application-oriented computer platform with integrated container management and the Edge OS Runtime running on it to the central cloud portal, via which the docker containers are deployed to the edge devices, through to turnkey containers for communication applications.

Gateways and switches, devices for network diagnostics as well as masters and bridges for the wireless connection of IO-Link sensors round off the automation portfolio.