Client access license

Last updated

A client access license (CAL) is a commercial software license that allows client computers to use server software services. Most commercial desktop apps are licensed so that payment is required for each installation, but some server products can be licensed so that payment is required for each device or user that accesses the service provided by the software. For example, an instance of Windows Server 2016 for which ten User CALs are purchased allows 10 distinct users to access the server. [1] [2] [3] [4]

Contents

Licensing

Commercial apps are licensed to end users or businesses: in a legally binding agreement between the proprietor of the software (the "licensor") and the end user or business (the "licensee"), the licensor gives permission to the licensee to use the app under certain limitations, which are set forth in the license agreement. In the case of Microsoft, the consumer retail or "off-the-shelf" products generally use very similar licence agreements, allowing the licensee to use the software on one computer, subject to the usual terms and conditions. For businesses, Microsoft offers several types of licensing schemes for a range of their products, which are designed to be cost effective, flexible, or both. [5]

Commercial server software, such as Windows Server 2003 and SQL Server 2005 require licenses that are more expensive than those which are purchased for desktop software like Windows Vista. All clients that connect to these server products must have a license to connect in order to use their services. These special purpose licenses come in the form of a CAL.

Enforcement

A CAL legally permits client computers to connect to commercial server software. They usually come in the form of a certificate of authenticity (CoA) and a license key, which is sometimes attached to the certificate itself. The various editions of most of Microsoft's server software usually include a small number of CALs, and this allows the software to be used by either a few users or a few computers, depending on the CAL licensing mode. If more clients need to access the server, then additional CALs must be purchased.

Microsoft Server products require a CAL for each unique client regardless of how many will be connecting at any single point in time. [6] Some of Microsoft's server software programs do not require CALs at all, as is the case of Windows Server Web Edition. Microsoft SQL Server can be licensed for CALs, or alternatively by CPU cores.

Types

CALs apply to either a "device" (as defined in the license agreement) or a "user". A business is free to choose either mode.

With user CALs, each CAL allows one user to connect to the server software whenever they need to. Once the CAL has been allocated to that user, another user cannot use it. Any number of CALs can be purchased to allow five, five hundred, or any number of users to connect to the server. With user CALs, each user can connect to the server software from any number of devices. The devices are not counted, but only a set number of users can connect.

Per-device mode operates in much the same way, but limits the number of devices which can connect, rather than the number of users. One CAL enables one device to connect to and use the server software, regardless of how many users connect from that particular device.

Although User and Device CALs are currently the same price, they may not be used interchangeably, and cannot be switched without buying new CALs. The price of User CALs has increased since December 2012 (in the UK), although the device CAL remains the same.

Combined schemes

The Core CAL is a special CAL offered by Microsoft through corporate license agreements such as Enterprise, Select or Open Value. The Core CAL is a combination of CALs for Windows Server, Exchange Server, SharePoint Server, System Center Configuration Client Management License, Lync Server, and Forefront Endpoint Subscription License. Core CALs are approximately 30 percent cheaper than the sum of the aforementioned licenses.

With the release of the 2007 products, Microsoft started offering the Enterprise CAL Suite. The Enterprise CAL Suite combines 15 CALs, including the Core CAL combination, Enterprise functionality of Exchange, Lync, and SharePoint Servers, as well as System Center Data Protection Manager, Operation Manager, and Service Manager Client Management Licences. [7] As for the Core CALs, Enterprise CALs are only available through Open, Enterprise or Select agreements.

Software editions

CALs usually enable connectivity to server software regardless of the edition of the software. [8] For example, CALs purchased to enable client connectivity with Windows Server 2003 Enterprise Edition can be used with Windows Server 2003 Datacenter Edition. However, backwards compatibility is generally assured. For example, Windows Server 2012 CALs can not only be used to access servers running on Windows Server 2012, but they can be used to access one of the servers running Windows Server 2008, Windows Server 2008 R2, Windows Server 2003, and any previous versions at any given time.

Terminal Services

Terminal Services is a function of Microsoft Windows that allows several types of connections to the server components of the system. Windows Server versions prior to 2003 do not necessarily require the use of specialized Terminal Services CALs; rather, clients which are of at least the same or lower version of the operating system are allowed access automatically. For example, Windows NT 4.0 clients may connect to Windows NT 4.0 terminal servers but not Windows 2000 or later; Windows 2000 or Windows XP clients may connect to Windows NT 4.0 or Windows 2000 terminal servers. This is called the equivalency license. [9]

The system for enforcing the number of TS CALs ("Microsoft Enforced Licensing") used on versions later than NT was abused by the "FLAME" malware, leading to a patch in 2012 restricting the Certificate Creation system used for Terminal Services.

The number of per-user TS CALs on Windows 2008 is not enforced: supposedly, this was because Microsoft did not have time to finalize technical enforcement before the release of the operating system. [10]

See also

Related Research Articles

<span class="mw-page-title-main">Thin client</span> Non-powerful computer optimized for remote server access

In computer networking, a thin client, sometimes called slim client or lean client, is a simple (low-performance) computer that has been optimized for establishing a remote connection with a server-based computing environment. They are sometimes known as network computers, or in their simplest form as zero clients. The server does most of the work, which can include launching software programs, performing calculations, and storing data. This contrasts with a rich client or a conventional personal computer; the former is also intended for working in a client–server model but has significant local processing power, while the latter aims to perform its function mostly locally.

<span class="mw-page-title-main">Windows Update</span> Software update distribution service for Microsoft Windows

Windows Update is a Microsoft service for the Windows 9x and Windows NT families of the Microsoft Windows operating system, which automates downloading and installing Microsoft Windows software updates over the Internet. The service delivers software updates for Windows, as well as the various Microsoft antivirus products, including Windows Defender and Microsoft Security Essentials. Since its inception, Microsoft has introduced two extensions of the service: Microsoft Update and Windows Update for Business. The former expands the core service to include other Microsoft products, such as Microsoft Office and Microsoft Expression Studio. The latter is available to business editions of Windows 10 and permits postponing updates or receiving updates only after they have undergone rigorous testing.

Microsoft Exchange Server is a mail server and calendaring server developed by Microsoft. It runs exclusively on Windows Server operating systems.

Remote Desktop Protocol (RDP) is a proprietary protocol developed by Microsoft Corporation which provides a user with a graphical interface to connect to another computer over a network connection. The user employs RDP client software for this purpose, while the other computer must run RDP server software.

<span class="mw-page-title-main">Windows NT 3.1</span> First major release of Windows NT, released in 1993

Windows NT 3.1 is the first major release of the Windows NT operating system developed by Microsoft, released on July 27, 1993.

A remote access service (RAS) is any combination of hardware and software to enable the remote access tools or information that typically reside on a network of IT devices.

NX technology, commonly known as NX or NoMachine, is a remote access and remote control computer software, allowing remote desktop access and maintenance of computers. It is developed by the Luxembourg-based company NoMachine S.à r.l.. NoMachine is proprietary software and is free-of-charge for non-commercial use.

Remote administration refers to any method of controlling a computer or other Internet-connected device, such as a smartphone, from a remote location. There are many commercially available and free-to-use software that make remote administration easy to set up and use. Remote administration is often used when it's difficult or impractical to be physically near a system in order to use it or troubleshoot it. Many server administrators also use remote administration to control the servers around the world at remote locations. It is also used by companies and corporations to improve overall productivity as well as promote remote work. It may also refer to both legal and illegal remote administration.

<span class="mw-page-title-main">Skype for Business Server</span> Real-time communications server software

Skype for Business Server is real-time communications server software that provides the infrastructure for enterprise instant messaging, presence, VoIP, ad hoc and structured conferences and PSTN connectivity through a third-party gateway or SIP trunk. These features are available within an organization, between organizations and with external users on the public internet or standard phones.

<span class="mw-page-title-main">Windows Server Essentials</span> Business software suite by Microsoft

Windows Server Essentials is an integrated server suite from Microsoft for businesses with no more than 25 users or 50 devices. It includes Windows Server, Exchange Server, Windows SharePoint Services, and Microsoft Outlook. Application server technologies are tightly integrated to provide and offer management benefits such as integrated setup, enhanced monitoring, Remote Web Workplace, a unified management console, and remote access.

Microsoft Office Live Meeting is a discontinued commercial subscription-based web conferencing service operated by Microsoft. Live Meeting included software installed on client PCs and used a central server for all clients to connect to. The service was shut down on December 31, 2017. Microsoft now produces Skype for Business which is an enterprise Unified Communications product, that can be rolled out either on-premises or in the cloud.

<span class="mw-page-title-main">Skype for Business</span> Enterprise instant messaging and video conferencing software by Microsoft

Skype for Business is an enterprise software application for instant messaging and videotelephony developed by Microsoft as part of the Microsoft 365 suite. It is designed for use with the on-premises Skype for Business Server software, and a software as a service version offered as part of 365. It supports text, audio, and video chat, and integrates with Microsoft 365 components such as Exchange and SharePoint.

<span class="mw-page-title-main">Windows Server Update Services</span> Update distribution system for Windows Server

Windows Server Update Services (WSUS), previously known as Software Update Services (SUS), is a computer program and network service developed by Microsoft Corporation that enables administrators to manage the distribution of updates and hotfixes released for Microsoft products to computers in a corporate environment. WSUS downloads these updates from the Microsoft Update website and then distributes them to computers on a network. WSUS is an integral component of Windows Server.

In software licensing, volume licensing is the practice of using one license to authorize software on a large number of computers and/or for a large number of users. Customers of such licensing schemes are typically business, governmental or educational institutions, with prices for volume licensing varying depending on the type, quantity and applicable subscription-term. For example, Microsoft software available through volume-licensing programs includes Microsoft Windows and Microsoft Office.

Desktop virtualization is a software technology that separates the desktop environment and associated application software from the physical client device that is used to access it.

In computing, the term remote desktop refers to a software- or operating system feature that allows a personal computer's desktop environment to be run remotely from one system, while being displayed on a separate client device. Remote desktop applications have varying features. Some allow attaching to an existing user's session and "remote controlling", either displaying the remote control session or blanking the screen. Taking over a desktop remotely is a form of remote administration.

Adaptive Internet Protocol (AIP) is a multi-channel protocol that allows an application running on any of multiple platforms to be displayed on any of a wide range of client systems. It supports rich remote display and input services with a number of display options to deliver the presentation of the remote applications onto the local display either as a standalone window, or within a contained remote environment delivered full-screen or in a standalone window. The protocol also supports audio, printing, and other device mapping services.

Remote Desktop Services (RDS), known as Terminal Services in Windows Server 2008 and earlier, is one of the components of Microsoft Windows that allow a user to initiate and control an interactive session on a remote computer or virtual machine over a network connection. RDS was first released in 1998 as Terminal Server in Windows NT 4.0 Terminal Server Edition, a stand-alone edition of Windows NT 4.0 Server that allowed users to log in remotely. Starting with Windows 2000, it was integrated under the name of Terminal Services as an optional component in the server editions of the Windows NT family of operating systems, receiving updates and improvements with each version of Windows. Terminal Services were then renamed to Remote Desktop Services with Windows Server 2008 R2 in 2009.

Citrix Virtual Apps is an application virtualization software produced by Citrix Systems that allows Windows applications to be accessed via individual devices from a shared server or cloud system.

References

  1. ↑ "Client Access Licenses (CAL) & Management Licenses | Microsoft Volume Licensing". www.microsoft.com. Retrieved 2024-02-29.
  2. ↑ "What are RDS CALs and how should IT use them? | TechTarget". Virtual Desktop. Retrieved 2024-02-29.
  3. ↑ "Windows Server 2022 Availability Announcement - News - LATAM Partner One". www.microsoft.com. Retrieved 2024-02-29.
  4. ↑ Anderson, Tim. "Surge in home working highlights Microsoft licensing issue: If you are not on subscription, working remotely is a premium feature". www.theregister.com. Retrieved 2024-02-29.
  5. ↑ Microsoft Licensing
  6. ↑ Microsoft CAL Licensing Guide, Microsoft
  7. ↑ http://www.mslicensing.fr/theorie/core-cal-vs-enteeprise-cal%5B%5D Differences between Core CAL and Enterprise CAL (in French)
  8. ↑ Volume Licensing for Microsoft Products and Online Services, Microsoft
  9. ↑ "Licensing Terminal Server in Windows Server 2003 R2". Microsoft . Archived from the original on 2010-02-12. Retrieved 2010-02-17.
  10. ↑ Changes to Windows Server 2008 Terminal Server Licensing (Part 2) Archived 2012-09-06 at archive.today

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.