What is a VPN Concentrator?

As businesses continue to embrace remote work, ensuring secure access to company resources has never been more critical. One tool that stands as a cornerstone of secure remote access is a Virtual Private Network, or VPN. But what happens when a company has hundreds or thousands of employees all connecting remotely? This is where a VPN concentrator comes into play. In this comprehensive guide, we will demystify the concept of a VPN concentrator, explaining its function, importance, and role in maintaining secure, scalable remote access to network resources. Whether you're a business leader, IT professional, or simply a technology enthusiast, our aim is to enhance your understanding of VPN concentrators and how they contribute to the wider landscape of cybersecurity.

Read on to find out what a VPN concentrator is and how it works.

What is a VPN concentrator?

A VPN concentrator is a hardware device that allows businesses to manage multiple VPNs more easily. By consolidating multiple VPNs into a single device, a VPN concentrator can simplify the process of managing multiple VPNs and help to ensure that they continue to function properly. 

Think of it as a central router that manages the VPN's infrastructure. The VPN concentrator enables control over the entire corporate VPN connection. A key benefit of a VPN concentrator is that it saves you the resources you would have used to buy and manage extra hardware such as consoles. You only need one concentrator and with that you can control your entire VPN network. A single VPN concentrator can accommodate over 500 simultaneous connections, making it perfect for most businesses. So if you have 500 employees, for example, you can connect all their devices to one VPN concentrator from where the administrator is able to easily monitor and supervise.

For businesses, VPN concentrators can provide a cost-effective way to connect multiple locations to a single VPN network.

Also read: Common vulnerabilities threatening businesses networks

How does a VPN concentrator work?

A VPN concentrator creates multiple encrypted tunnels between a centralized network and remote clients. It establishes an encrypted server between specific VPN nodes. The VPN concentrator processes users’ IP addresses, and directs web traffic through encrypted tunnels before it reaches the centralized network.

The concentrator will encrypt both the incoming and outgoing  traffic. It implements security protocols that make it impossible for third parties to penetrate the tunnels. When a VPN concentrator receives incoming data, it includes additional information as the data is traveling over a public network. Once it reaches the destination, the device will decrypt it so the user can receive the original data.

A VPN concentrator is used with client software. When using a VPN concentrator, you will start the software that communicates with the VPN concentrator. Then, the software will communicate using the encrypted tunnel to the VPN concentrator. The VPN concentrator takes that data, encrypts it, and sends it to the central network. When it’s time to send back the information, the VPN concentrator will take the data, encrypt it and send it over the encrypted tunnel back to your computer.

The VPN tunnel is not always there. It is created on demand. So, when you’re done passing data to the centralized network, you can turn off the client software. This will sever the encrypted connection, and you can return to using the public network as usual.

Key features of  VPN concentrators

Any VPN concentrator will have a couple of features which are the foundation of what a concentrator can do or not do. Here are the common features that cut across all VPN concentrators:

VPN auditing

A VPN concentrator always maintains a comprehensive record of how the VPN  connections are being used across the company's network. Some of the details that are constantly captured by the auditing feature include the number of users logged in at any one time and the specific resources they are accessing.

Multi-Site interconnectivity

This means that a device can use different VPNs with different VPN concentrators to connect to different resources. For example, an employee can connect to one site with one VPN then at the same time connect to another site with a different VPN. These two VPNs can be managed by different concentrators.

Multiple tenancy

This feature makes it possible for administrators to segment sessions for different users. So you can, for example, use a concentrator to provide employee access to office resources but go a head to enable totally separate VPN connections for each employee. This means that the employees are not using the same VPN connection. The obvious benefit of this feature is a much more enhanced security.

VPN concentrators v. VPN routers

The debate over VPN concentrators and VPN routers is always on. Some believe there is not much difference between VPN concentrators and VPN routers. This is not true, as both have fundamental differences when it comes to what they can do. 

One key function that VPN routers lack compared to VPN concentrators is the ability to manage complex VPN structures, especially those involving numerous encrypted tunnels.

It's also important to note that while VPN concentrators come with alternatives for SSL VPNs, VPN routers can only accommodate SSL VPN connections. While VPN routers can work perfectly fine in small operations, they cannot perform for big organizations that run complex VPN networks. You'll face an uphill task trying to configure a VPN router to manage multiple VPNs. VPN concentrators on the other hand come already equipped for this task, and in fact this is the very type of work that VPN concentrators are built for.

Which VPN concentrators are the best?

The VPN concentrators manufactured by Cisco, SonicWALL, Shore Tel, HP, and Mako Networks are some of the best in the market. You might also want to consider open source solutions from initiatives such as OpenVPN and Native Linux implementations.

The exact type you need for your organization will depend on the number of VPNs you would like to manage as well as the functionalities that are most important for your operations.  

VPN concentrators are most common in large businesses and militaries where they help teams to achieve greater efficiency and productivity. In addition, they provide sophisticated network protection that’s not easy to achieve using VPN alone.

Conclusion

VPN concentrators essentially make it easy to coordinate and manage multiple VPN networks. They are perfect for businesses that run multiple VPN networks with the need for constant tweaking of VPN functions. Instead of employing several administrators to help manage your VPN network as is the case with traditional VPN management, you only need one admin to oversee the entire network. This will save you a lot of costs and most importantly increases the productivity of your workforce. 

As businesses increasingly rely on VPNs to maintain privacy, VPN concentrators are likely to become more popular as part of the essential IT needs, making them an essential tool for any business regardless of size.