IoT Glossary

What is OpenVPN?

OpenVPN is one of the most popular methods for securing private networks.

What is OpenVPN?

OpenVPN is one of the most popular methods for securing virtual private networks. 

Discover more about how an OpenVPN solution can help to ensure secure network connectivity for scattered devices, including IoT deployments.

What is OpenVPN and how does it work?

A virtual private network (VPN) provides a secure connection between two points in a network (e.g. an IoT device and a server). It effectively creates a private communication ‘tunnel’, enabling users to send and receive data across the public internet as if they were directly connected to a private network.

All VPNs require a system to determine how data is routed between devices and how it is protected in transit. OpenVPN is one of the most popular of these systems. Here are its key features:

Establishing a tunnel

With OpenVPN, a communication tunnel can be set up using one of two protocols: TCP (Transmission Control Protocol), or UDP (User Datagram Protocol). TCP has particularly strong in-built protocols for guaranteeing data delivery and avoiding errors, so it’s a good option for IoT devices that transmit critical data (e.g. industrial monitoring and medical data).

UDP is a simpler protocol designed for speed. It’s useful if your devices which need to transmit data in real-time (e.g. video surveillance) or on devices which transmit small amounts of regular data which is not time sensitive. The UDP protocol has lower processing and memory requirements so is better for smaller, lower-cost IoT sensor type devices.


To secure the flow of data, OpenVPN uses SSL/TLS (Secure Sockets Layer / Transport Layer Security) protocols. This is the same type of technology used to protect most websites. It provides a reliable way for devices to generate and exchange encryption keys, to ensure that only authorised devices or users access the network, and to verify that data has not been altered in transit.

What is an OpenVPN server used for?

As its name suggests, OpenVPN is an open-sourced technology. This means that the software behind it can be downloaded by anyone. So in theory, any business could create their own OpenVPN solution and set up their own VPN server.

In practice, however, while access to the code is free, configuring your own VPN from scratch requires considerable internal know-how and resources. This is why the vast majority of businesses use OpenVPN through a VPN provider.

This way, you can ensure that all your devices are properly equipped and configured. A specialist business OpenVPN server is specifically designed for multiple users and devices. This ensures secure transmission of data across your network, while also making it easier to manage large numbers of IoT devices in the field.

Is OpenVPN safe to use?

OpenVPN uses 256-bit OpenSSL encryption as standard. This makes it a very secure VPN system, helping to ensure that your data is not intercepted or tampered with in transmission.

The protocol’s open-source nature also helps to make OpenVPN a safe option for your business. The code behind the protocol is constantly being tweaked and updated by a large community of developers. It means that bugs and security vulnerabilities can be identified and addressed at an early stage.

What is the difference between OpenVPN and VPN?

When you see the term, ‘Open’ VPN, it simply indicates that the VPN in question is built using OpenVPN software.

For businesses, the main alternative to OpenVPN is IPSec (Internet Protocol Security). This protocol doesn’t rely on SSL/TLS for encryption and requires a static IP address (which isn’t always suitable for a lot of IoT use cases). It’s regarded as a highly secure protocol, although it can be expensive to set up and maintain.

IPSec is a good option if you need to transmit very sensitive data from static devices. OpenVPN is a more popular option for general business use cases.

What are the advantages and disadvantages of OpenVPN?



OpenVPN can be run on a wide variety of platforms, including Linux, Windows, macOS, iOS and Android. You also have a choice of communication tunnels (TCP or UDP). This makes it a flexible option, suitable for a wide range of IoT use cases. These include applications linked to internal business processes (e.g. asset tracking and industrial monitoring) as well as customer-facing devices.


With the ability to use 256-bit encryption, OpenVPN provides precisely the level of protection required to safeguard data against interception during transmission.


Compared to IPSec, an OpenVPN system can be set up rapidly and at a low cost. Although it involves installation of client software on endpoint devices, it does not generally require modifications to the hardware.


Connection speeds

Generally, OpenVPN offers a highly stable connection. However, due largely to the strong level of encryption it offers, users might occasionally experience some occasional drop-offs in connection speeds.

Manual setup

Manually setting up and maintaining an OpenVPN system requires expertise. It’s the reason why most businesses deploy the technology through a specialist VPN provider.

Why should you use OpenVPN?

Your optimum choice of VPN technology depends largely on the type of application you are deploying, as well as the level of sensitivity of the data you are transmitting.

However, in a lot of IoT use cases, OpenVPN provides the level of data protection businesses need, while also providing enough flexibility to tweak the configuration to match their precise usage requirements.

Find out more

For an expert assessment of your connectivity needs and to discover the best fit M2M options for your business, speak to Wireless Logic today.

For more information about a wide range of IoT connectivity options, explore our glossary.

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