What is TCP?
Transmission Control Protocol (TCP) is a communication standard that enables computing devices and application programs to exchange messages over a network. It is designed to transmit packets across the internet and ensure successful data and message delivery over networks.
TCP is one of the fundamental standards that defines the rules of the internet and is included in the standards defined by the Internet Engineering Task Force (IETF). It is one of the most commonly used protocols in digital network communications and ensures end-to-end data delivery.
TCP organizes data so that it can be transmitted between a server and a client, and guarantees the integrity of the data being communicated over a network. Before transmitting data, TCP establishes a connection between a source and destination and ensures it remains live until communication begins. It then breaks large amounts of data into smaller packets while ensuring data integrity throughout the process.
As a result, high-level protocols that need to transmit data typically use the TCP protocol. Examples include peer-to-peer sharing methods like File Transfer Protocol (FTP), Secure Shell (SSH), and Telnet. It is also used to send and receive email through Internet Message Access Protocol (IMAP), Post Office Protocol (POP), and Simple Mail Transfer Protocol (SMTP), and for web access through the Hypertext Transfer Protocol (HTTP).
An alternative to TCP in networking is the User Datagram Protocol (UDP), which is used to establish low-latency connections between applications and decrease transmission time. TCP can be an expensive network tool as it includes measures to handle absent or corrupted packets and protects data delivery with controls like acknowledgments, connection startup, and flow control.
UDP does not provide error correction or packet sequencing nor does it signal a destination before delivering data, which makes it less reliable but less expensive. As such, it is a good option for time-sensitive situations, such as Domain Name System (DNS) lookup, Voice over Internet Protocol (VoIP), and streaming media.
What is IP?
TThe Internet Protocol (IP) is a method for transmitting data across the internet from one device to another. Each device has a unique IP address that enables it to communicate and exchange data with other devices on the internet. It is the primary communication protocol responsible for defining how devices and applications exchange data and messages with each other.
IP operates within the internet layer of the TCP/IP protocol suite, which is a group of communication protocols split into four abstraction layers. Its main function is to deliver data packets between the source and destination devices or applications using methods and structures that place address information within data packets.
TCP and IP are separate protocols that work together to ensure data is delivered to its intended destination within a network. IP obtains and defines the IP address of the destination device or application, while TCP is responsible for transporting and routing data through the network architecture and ensuring it is delivered to the correct destination. The combination of TCP/IP enables communication between devices over long distances and allows for efficient transfer of data.
TCP/IP is frequently used together and relies on each other for data to have a destination and safely reach it. With the right security protocols in place, this combination allows for safe and secure data transfer between two or more devices.
How Does Transmission Control Protocol (TCP)/IP Work?
The TCP/IP model is the primary method of data communication used on the internet. It was initially created by the US Department of Defense to facilitate the accurate and reliable transmission of data between devices. To avoid resending the whole message in case of a transmission problem, messages are broken down into packets. Once they reach their intended destination, packets are automatically reassembled. Different packets can take different routes between the source and destination computers, depending on network congestion and availability.
TCP/IP divides communication tasks into layers to maintain standardized processes, preventing hardware and software providers from managing the processes themselves. Before a data packet is received by the destination device, it must pass through four layers, and then TCP/IP goes through the layers in reverse order to restore the message to its original format.
TCP is a connection-based protocol that establishes and maintains a connection between applications or devices until data exchange is complete. It determines how the message should be broken down into packets, numbers and reassembles the packets, and sends them to other network devices such as routers, security gateways, and switches before delivering them to their destination. TCP handles the transmission of any dropped packets, manages flow control, and ensures all packets reach their destination.
A practical example of how TCP/IP works is when an email is sent using SMTP from an email server. The TCP layer on the server divides the message into packets, numbers them, and forwards them to the IP layer, which then transports each packet to the destination email server. Upon arrival, the packets are handed back to the TCP layer to be reassembled into the original message format and returned to the email server, which then delivers the message to the user’s email inbox.
TCP/IP uses a three-way handshake to establish a connection between a device and a server. This ensures that multiple TCP socket connections can be transferred in both directions concurrently. The device and server must synchronize and acknowledge packets before communication begins, then negotiate, separate, and transfer TCP socket connections.
The 4 Layers of the TCP/IP Model
The TCP/IP model is a framework that specifies how data should be transmitted between devices, enabling communication over networks and large distances. It is divided into four layers, which establish the standards for data exchange and represent how data is handled and packaged during delivery between applications, devices, and servers.
The four layers of the TCP/IP model are:
- Datalink layer: This layer is responsible for how data should be sent, handling the physical act of sending and receiving data, and transmitting data between applications or devices on a network. It defines how data should be signaled by hardware and other transmission devices on a network, such as a computer’s device driver, an Ethernet cable, a network interface card (NIC), or a wireless network. It is also known as the link layer, network access layer, network interface layer, or physical layer, and it combines the physical and data link layers of the Open Systems Interconnection (OSI) model, which standardizes communications functions on computing and telecommunications systems.
- Internet layer: This layer is responsible for sending packets from a network and controlling their movement across a network to ensure they reach their destination. It provides the functions and procedures for transferring data sequences between applications and devices across networks.
- Transport layer: This layer is responsible for providing a reliable data connection between the original application or device and its intended destination. Data is divided into packets and numbered to create a sequence, and the transport layer determines how much data must be sent, where it should be sent, and at what rate. It ensures that data packets are sent without errors and in sequence, and it obtains acknowledgment that the destination device has received the data packets.
- Application layer: This layer refers to programs that need TCP/IP to help them communicate with each other. Users typically interact with this layer, which includes email systems, messaging platforms, and other software applications. It combines the session, presentation, and application layers of the OSI model.
Are Your Data Packets Private Over TCP/IP?
Data packets sent over TCP/IP are not private, which means they can be seen or intercepted. For this reason, it is vital to avoid using public Wi-Fi networks for sending private data and to ensure information is encrypted. One way to encrypt data being shared through TCP/IP is through a virtual private network (VPN).
What is My TCP/IP Address?
Having a TCP/IP address is crucial for configuring a network, especially for local networks. It is also possible to easily find a public IP address by using various online tools that quickly detect the IP address, as well as other related information such as the user’s host IP address, internet service provider (ISP), remote port, and device and browser details.
Alternatively, users can find their TCP/IP address through the administration page of their router, which displays the current public IP address, the router’s IP address, subnet mask, and other relevant network information.
How Fortinet Can Help
- Fortinet offers FortiGate Internet Protocol security (IPsec)/secure sockets layer (SSL) VPN solutions that enable secure sharing and transmission of data through the TCP/IP model. These scalable VPNs protect organizations and their users from advanced cyber attacks like man-in-the-middle (MITM) attacks and the risk of data loss while data is in motion at high speed. This is particularly important for data being transmitted through TCP/IP, which does not provide protection for data packets while they are in motion.
- Fortinet’s VPN solutions ensure secure communication across the internet, multiple networks, and between endpoints, using both IPsec and SSL technologies. The Fortinet FortiASIC hardware acceleration guarantees high-performance communication and data privacy.
- By encrypting data being transmitted between applications and devices, Fortinet’s VPNs create secure connections and mask the users’ IP addresses, thereby creating a private connection for sharing data regardless of the security of the internet connection used. This eliminates the risk of sensitive data exposure to third parties during transfer over TCP/IP and also hides the users’ browsing histories, IP addresses, locations, web activities, and other device information.