Windows Server 2019 licensing requirements for Remote Desktop Service (RDS) to enable remote working

When an organization purchases Windows Server OEM licensing with their HPE ProLiant server, it's always important to make sure they understand their complete licensing needs, especially client access licenses (CALs). But now, that conversation may be more important than ever. That's because many businesses are considering using Microsoft Remote Desktop Services (RDS) to enable technologies that support remote workers. Let's take a closer look at the Windows Server licensing required for utilizing RDS, to help businesses make smart licensing decisions.

Core Based Licensing vs Processor Based Licensing
It is important to understand the licensing models for each edition of Windows Server 2019 and how they work. 

  • Windows Server 2019 Essentials follows a processor-based licensing model. This means that licensing is based on the number of server processors
  • Windows Server 2019 Standard and Windows Server 2019 Datacenter follow a core-based licensing model, where licensing requirements are determined based on the number of server cores instead of the number of processors. 

For today's blog, we will focus on core-based licensing rules and requirements. 

Now, let's jump in to the different types of licenses starting with Base Licenses. 

Base Licenses
The first rule of Windows Server core-based licensing is that every server requires a minimum of a single Windows Server 2019 base license. Both Windows Server 2019 Standard and Windows Server 2019 Datacenter base licenses cover up to 16 processor cores.

However, these licenses differ when you look at Virtual Machine licensing: Windows Server 2019 Standard provides licensing for 2 VMs, while Windows Server 2019 Datacenter permits unlimited VMs.

Additional Licenses
Another important rule of Windows Server core-based licensing is that all physical cores of the server must be licensed. This means, if the server has more than 16 cores, Additional Licenses must be utilized. In addition, for every 2 VMs added in Windows Server 2019 Standard, all of the cores of the server must be licensed again.

Windows Server 2019 Additional Licenses are available from HPE in increments of 2, 4, and 16 cores. For more details on base licenses and additional licenses in multi-OS or virtualized operating environments, read The Ultimate Guide to Windows Server 2019 Licensing.

Windows Server User/Device Client Access Licenses (CALs)
When a customer purchases Windows Server Base/Additional Licenses from HPE with their new HPE Gen10 server, it gives them the right to install the OS onto the server. But it’s important to understand that the Windows Server licensing is only part of the equation. In addition, a business needs to purchase Windows Server CALs for either every user or every device that is going to access the server running Windows Server.

  • User CALs are best when: Employees access the corporate network using multiple devices or if there are simply more devices than users in the organization. In this case, your customer would need to purchase a user CAL for every user who accesses the server, regardless of the number of devices they use for that access.
  • Device CALs are best when: Employees share devices, such as shift workers, or there are likely more employees than devices in the organization. In this case, your customer would need to purchase a device CAL for every device used to access the server.

Remote Desktop Service (RDS) CALs
If users are going to access programs or the full desktop remotely using RDS, they are going to need RDS CALs in addition to the Windows Server CALs we already covered. RDS CALs are also available as per user or per device, but in a work-from-home scenario, it probably will make the most sense for customers to choose the per user option for both Windows Server CALs and RDS CALs.

An RDS licensing example

If a customer wants to purchase new technology to support 30 light users, they might choose an HPE ProLiant DL360 Gen10 Server with Windows Server 2019 Standard. First, you need to know how many cores the DL360 has (up to 28). To license 28 cores, they would need a Windows Server 2019 Standard Base License (which covers 16 cores) as well as Windows Server 2019 Standard Additional licensing to cover an additional 12 cores. In addition, they would need 30 Windows Server User CALs and 30 RDS User CALs.  

Now is also a great time to check in with current customers to see if their CAL needs have changed—especially for RDS CALs. And remember that all types of CALs are available from HPE in packs of 1, 5, 10, or 50, to help your customer get just the right solution for their needs.


When you check in with your customers, you may find that they need to upgrade their server, OS, or both. For these customers, we recommend HPE Small Business Solutions for Small Office Deployment. They’re a one‑stop shop for complete solutions built on HPE ProLiant Gen10 servers and Windows Server 2019. They come in a variety of configuration options that are sized right for health care offices, retail stores, start-ups, and other businesses that want to empower employees with work-from-home productivity.


Have questions about CALs, HPE OEM Microsoft products/solutions, Windows Server 2019, or HPE ProLiant servers? Join the Coffee Coaching community to keep up with the latest HPE OEM Microsoft news and interact with HPE and Microsoft experts.

Willa Anderson
Hewlett Packard Enterprise

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Willa manages the HPE | Microsoft Coffee Coaching program. Follow along to learn more about the latest HPE OEM Microsoft product releases and how the HPE Microsoft partnership can benefit partners and customers.