What is the Minimum Required Licenses?
The minimum required license is 1 ‘Single or Upstream‘ license.
Do you have a Single WSUS Server?
The most basic WSUS deployment consists of a server inside the corporate firewall that serves client computers on a private intranet. The WSUS server connects to Microsoft Update to download updates. If you have a single WSUS server licensing WSUS Automated Maintenance requires 1 ‘Single or Upstream’ license.
Do you have Multiple WSUS Servers?
A WSUS deployment can consist of multiple connected servers. When you connect multiple WSUS servers, you create at least one upstream WSUS server and at least one downstream WSUS server. This configuration creates a hierarchy of WSUS servers, as shown in the following image:
Root WSUS Upstream Server
A root WSUS upstream server is defined as a system that synchronizes directly with Microsoft Update. Each root WSUS upstream server requires a ‘Single or Upstream’ license.
A downstream replica server, also called centralized administration, works by having an upstream WSUS server that shares updates, approval status, and computer groups with downstream servers. Replica servers inherit update approvals and are not administered separately from the upstream WSUS server. Each downstream replica server requires a ‘Downstream’ license.
A downstream autonomous server, also called distributed administration, is the default installation option for WSUS. In Autonomous mode, an upstream WSUS server shares updates with downstream servers during synchronization. Downstream autonomous servers are administered separately, and they do not receive update approval status or computer group information from the upstream server. Each downstream autonomous server requires a ‘Downstream’ license.
Do you have a WSUS deployment for disconnected networks?
Do you have System Center Configuration Manager (SCCM)?
System Center Configuration Manager (SCCM) uses Software Update Points (SUP) in the distribution of patches within your network. You can install more than one software update points on a site. The first software update point that you install is configured as the synchronization source and is installed on the central administration site and/or the primary site. The software update point interacts with the WSUS services to configure the software update settings and to request synchronization of software updates metadata.
Root WSUS Upstream Server
The other software update points on the site are configured as replicas of the first software update point. The first installation of the software update point is on the Root WSUS Upstream Server. A root WSUS upstream server is defined as a system that synchronizes directly with Microsoft Update and requires a ‘Single or Upstream’ license.
The other software update points on the site are configured as downstream replicas of the first software update point. Each downstream replica server requires a ‘Downstream’ license.