LTSC: What is it, and when should it be used?

[John Wilcox]

Update 7/15/2019:  The content in this post applies to PC and laptop type devices converted to Windows 10 Enterprise LTSC, and not devices purchased with Windows 10 IoT Enterprise pre-installed. Examples of the latter include kiosks, medical equipment, and digital signs, i.e. use cases where devices are commonly treated as a whole system and are, therefore, “upgraded” by building and validating a new system, turning off the old device, and replacing it with a new, certified device. Organizations that leverage this approach are seeking the manageability and security of Windows 10 while staying on the same operating system version for the life of the device.

---

If you ask someone from Microsoft, or read industry guidance, about the best strategy for managing Windows 10 updates, the overarching recommendation is to use the Semi-Annual Channel (SAC) as the default servicing channel for Windows 10 devices. With the Semi-Annual Channel, devices receive two feature updates per year, and benefit from the best performance, user experience, security, and stability.

The Long-Term Servicing Channel (LTSC) is designed for Windows 10 devices and use cases where the key requirement is that functionality and features don’t change over time. Examples include medical systems (such as those used for MRI and CAT scans), industrial process controllers, and air traffic control devices. These devices share characteristics of embedded systems: they are typically designed for a specific purpose and are developed, tested, and certified before use. They are treated as a whole system and are, therefore, commonly “upgraded” by building and validating a new system, turning off the old device, and replacing it with the new, certified device.

We designed the LTSC with these types of use cases in mind, offering the promise that we will support each LTSC release for 10 years--and that features, and functionality will not change over the course of that 10-year lifecycle.

Differences between the Semi-Annual Channel and LTSC

As I noted above, Windows 10 devices in the Semi-Annual Channel receive twice-yearly feature updates, once in the spring and once in the fall. These updates contain new features, services, and other major changes. Security updates, optimizations, and other minor updates or patches are released every month thereafter.

To deliver on the commitment of no changes to features or functionality, a Windows 10 LTSC release does not contain any of the components of Windows 10 that may change over the life of the release. These components include Microsoft Edge (as a modern browser, it is constantly evolving to support the current modern browser web standards) as well as components/applications regularly updated via the Microsoft Store, such as Camera, Cortana, OneNote, and other modern apps that continue to advance with innovative improvements. 

Internet Explorer is included in Windows 10 LTSC releases as its feature set is not changing, even though it will continue to get security fixes for the life of a Windows 10 LTSC release.

The LTSC cadence

We create a new LTSC release approximately every three years, and each release contains all the new capabilities and support included in the Windows 10 features updates that have been released since the previous LTSC release. Unlike the year-and-month terminology employed to describe Windows 10 features updates (e.g. 1703 or 1809), LTSC releases are named with a specific year, such as Windows 10 Enterprise LTSC 2016 or Windows 10 Enterprise LTSC 2019, and they align to perpetual Office releases such as Office 2019.

Each LTSC release receives 10 years of servicing and support[i]. During the life of a LTSC release, you can upgrade your devices to the next or latest LTSC release free of charge using an in-place upgrade, or to any currently supported release of Windows 10. Because the LTSC is technically its own SKU, an upgrade is required from Windows 10 Enterprise LTSC to Windows 10 Enterprise, which supports the Semi-Annual Channel.

As with the Semi-Annual Channel, LTSC devices receive regular quality and security updates to ensure that device security stays up to date. While quality updates are available for Windows 10 Enterprise LTSC, you can choose to defer them using tools such as Windows Update for Business or System Center Configuration Manager.

Making a fully informed choice about the LTSC

Before its release and throughout the first year of Windows 10, many predicted that LTSC would be the preferred servicing channel for enterprise customers. This has turned out not to be the case, and the SAC is the predominant choice for enterprises today.

I’m currently working with a few early LTSC adopters who are now looking to unwind their LTSC deployments and shift to SAC. There are several reasons why using the LTSC can turn out to be the wrong fit for the Windows 10 devices in an organization. For example, one organization deployed LTSC to bring forward the same IT rules and image creation and management processes they had used since Windows XP, in this case to new Surface devices. You can imagine the reaction of their end users when they excitedly opened their new Surface devices, only to find that features such as Camera, Ink, and Pen did not work—and that they were missing many of the modern, touch friendly version of apps—because the devices had been “repaved” with a Windows 10 Enterprise LTSC release.

Another reason some organizations chose to adopt the LTSC centered around application compatibility. In talking with some of these organizations; however, initial concerns about application compatibility from release to release in their environment have proved to be a non-issue.

Considerations

All too often, I have seen strategic decisions about Windows 10 servicing options and the use of the Long-Term Servicing Channel driven by the wrong criteria; for example, IT professional familiarity prevailing over end user value and impact. The LTSC is designed for devices and use cases where features and functionality will not change. It provides 10 years of security servicing to a static Windows 10 feature set. If you are considering the LTSC for devices in your organization, please consider the following:

• Silicon support: Windows 10 Enterprise LTSC will support the currently released processors and chipsets at the time of release of the LTSC. When choosing to utilize the LTSC, you must factor hardware into your decision, making sure you have a long-term supply of devices and service components for the life of your expected usage of the device. If the hardware your device is using needs to be replaced in five years, do you have a replacement supply to support the version you are running? You also want to be sure you have a hardware solution that will provide you with extended driver/firmware support to match your expected lifecycle use of the LTSC for that device. (See the Lifecycle FAQ to learn more about the Windows Silicon Support Policy.)
• New peripheral support: Because the API and driver support models are not changing, the LTSC release you deploy may not support new hardware or peripherals that you need to use in your organization.
• Application support: With each Semi-Annual Channel release following an LTSC release, there is a growing gap in APIs and functionality between the current Windows API in use by most all devices, and previous LTSC releases. Many ISVs do not support LTSC editions for their applications, as they want their applications to use the latest innovation and capabilities to give users the best experience. This is the case with Office ProPlus, which does not support Windows 10 Enterprise LTSC releases as it relies on Windows 10 feature updates and the Semi-Annual Channel to deliver the best user experience with the latest capabilities. (If you were using Windows 10 Enterprise LTSC 2019, you would, therefore, need to use Office 2019.)
• Best security: Windows 10, with the latest feature update installed, is always the most secure release of Windows 10, offering the latest security capabilities and functionality.
• Best stability: Windows 10, with the latest feature update installed, has the latest performance and stability improvements.
• Greatest hardware choice: New devices target and ship with the latest Windows 10 release to light up new hardware capabilities and improvements.

Summary

The Long-Term Servicing Channel a tool designed for a specific job. When used for the right job, it’s a great solution, but when misaligned, it can be like trying to drive a screw with a hammer. It’s, at best, unsatisfying, and likely problematic at some point.

If you understand the considerations listed above, have secured hardware and support to align with the intended duration of usage, and have secured support for your applications, the LTSC can provide your organization with years of secure, static operation, with full servicing and support for its 10-year lifespan. For most use cases; however, I recommend the Semi-Annual Channel as the better option for security, stability, and hardware/application capabilities, and the overall experience of your end users.

To learn more, check out our on demand session from Microsoft Ignite on The pros and cons of LTSC in the enterprise.

---

[i] Ten years of support includes a minimum of five years Mainstream Support (during which both security and non-security updates are provided) and a minimum of five years Extended Support (during which only security updates are provided). Please see the Fixed Lifecycle Policy for Microsoft Business, Developer and Desktop Operating Systems for more detail.