Windows Server

– RDS CAL

This​‍​‌‍​‍‌​‍​‌‍​‍‌ is one of the commercially licensed software types. It is not software by itself. Every user or device that connects to a server to make use of the services of the server, such as a service for sharing files, printing, or authentication against a domain controller, will require a CAL. A license that permits a user or a device to be able to access server software services in a legal way is what a CAL is. Microsoft applies this scheme to their server products such as Windows Server, Exchange Server, and SQL ​‍​‌‍​‍‌​‍​‌‍​‍‌Server.

An​‍​‌‍​‍‌​‍​‌‍​‍‌ RDS CAL (Remote Desktop Services Client Access License) is a type of license that permits users or devices to establish a connection and make use of a Windows Server having the Remote Desktop Services (RDS) role. By having this license, the user or device gets the lawful access to the server's shared resources, such as virtual desktops and applications, via the Remote Desktop Protocol ​‍​‌‍​‍‌​‍​‌‍​‍‌(RDP).

RDS​‍​‌‍​‍‌​‍​‌‍​‍‌ CALs come in two varieties: Per-User RDS CAL and Per-Device RDS CAL. The correct selection of one is determined by the way the users and devices of your organization connect to the ​‍​‌‍​‍‌​‍​‌‍​‍‌server.

A​‍​‌‍​‍‌​‍​‌‍​‍‌ Per-User RDS CAL is a type of Remote Desktop Services Client Access License which is given to a particular user rather than a device. This licensing pattern is compatible with scenarios where a user accesses a remote desktop server through multiple devices.

The use of Per-User RDS CAL is limited to certain individuals and situations and is most effective in the following cases:

• Workers who use multiple locations and devices are the biggest beneficiaries of such a scheme. For example, a user may access the remote desktop via a work desktop, a personal laptop at home, and a smartphone or tablet while on a trip. One Per-User CAL is sufficient to cover all those connections.
• The model is also suitable for organizations with a flexible or RWP policy. Businesses that provide their employees with the liberty to work from different places and on different devices can use Per-User CALs to reduce their licensing costs.
• In case a company has more devices than users, this model is the one that makes economic sense. If you are in a situation where the number of devices outnumbers that of users, then you just need to get a license for each unique user regardless of how many devices they use to connect.
• Per-User CALs can be used by users in an Active Directory (AD) domain environment as they are linked to the user in Active Directory. While Per-Device CALs may be utilized in a workgroup environment, Per-User CALs usually require an AD domain for better functioning and monitoring by the licensing ​‍​‌‍​‍‌​‍​‌‍​‍‌server.

A​‍​‌‍​‍‌​‍​‌‍​‍‌ Per-Device RDS CAL (Remote Desktop Services Client Access License) is basically a license that is tied to a specific device. Whichever user that utilizes the particular device is licensed to access a Remote Desktop Services (RDS) server. The said licensing model is compatible with certain work environments and user cases only.

Here is the list and condition when a Per-Device RDS CAL would be the best option:

• In the case of a factory, a call center, or a hospital, one computer may be used by several employees throughout the day, such as across three different shifts. The way it works is that, instead of purchasing a separate Per-User CAL for every single staff member, you only need to have one Per-Device CAL for the computer.
• The device in libraries, hotel kiosks, or school computer labs may be used by numerous people; hence a Per-Device CAL will facilitate the licensing process by linking it to the machine rather than the constantly changing user group.
• Suppose you have 100 employees but only 50 computers, in that case, a Per-Device model would be more cost-efficient. The number of CALs that you would need to purchase is 50 instead of 100.
• Per-Device CALs can be supervised and controlled by the license server without the necessity of the devices being in an Active Directory domain. This implies that they are a viable option for less complicated network configurations that do not have a domain.
• In contrast to Per-User CALs, which sometimes are not strictly followed, the license server for Per-Device CALs has the capability to keep the restriction. For instance, if you have 5 Per-Device CALs and the sixth device tries to get access, the server will deny the connection. Thus, it can be used as a tool to facilitate compliance and resource ​‍​‌‍​‍‌​‍​‌‍​‍‌management.

You​‍​‌‍​‍‌​‍​‌‍​‍‌ can track Per-Device RDS CALs from Licensing Manager. Information on Per-User RDS CALs can only be obtained from the Active Directory environment and are not accessible in a workgroup ​‍​‌‍​‍‌​‍​‌‍​‍‌environment.

Per-Device lets you revoke up to 20% of RDS CALs. This is not possible with Per-User.

Temporary​‍​‌‍​‍‌​‍​‌‍​‍‌ RDS CALs belong to the Per-Device RDS CAL licensing model. They are not sold separately. Essentially, these are limited licenses provided by a Remote Desktop Licensing server.

They operate as follows:

1. First Connection: Upon a new device attaching for the initial time to an RD Session Host server in Per-Device licensing mode, the server communicates with the RD Licensing server for confirmation.
2. Temporary CAL Issuance: In response, the RD Licensing server grants that device a temporary RDS CAL. This allows the device to connect and, thus, the user can start their session although a permanent CAL hasn't been assigned yet.
3. Verification and Change: Following the user's log-in, the RD Session Host server instructs the Licensing server to consider the temporary CAL as verified. At the moment when that device accesses the network again, if there is a permanent Per-Device RDS CAL available on the license server, the temporary CAL is replaced with the permanent one.
4. End of Time: Normally, temporary RDS CALs come with a 90-day expiration period. If, for example, the device hasn't been provided with a permanent CAL by the license server within this period (maybe because no licenses are available), the temporary CAL will cease to function. Thus, the user won't be able to access the session.

Important Facts about Temporary RDS CALs:

• Temporary CALs only support the Per-Device licensing model. The Per-User licensing model doesn't have temporary CALs.
• An RD Licensing server is the one who issues temporary CALs automatically. There is no need for you to create or assign them manually.
• The temporary CAL is basically a buffer period. It allows you the time needed for the installation and activation of permanent licenses after the initial deployment, without interruption of user access from occurring.
• Upon expiry of the temporary CAL, users who are on that device will get logged off from their session, after an alarm period, which usually lasts for 60 minutes. This will happen until a legitimate permanent CAL becomes available.

Administrators should make sure that there are sufficient permanent RDS CALs placed on their licensing server. This will accommodate the safety of all devices that will be connected to the RDS environment and, as a result, it will prevent service ​‍​‌‍​‍‌​‍​‌‍​‍‌interruptions.