The WebSocket software requirement is IIS 8 or later.
To enable the Winsock interface for IIS under Windows 10
Select Programs and Features from the Control Panel.
Click the Turn Windows features on or off hyperlink on the left.
In the following order, expand:
Internet Information Services
World Wide Web Services
Application Development Features
Check the WebSocket Protocol check box and then click the OK button.
To enable the Winsock interface for Windows Server 2012
Log into your server using Remote Desktop.
Open the Server Manager.
Select the Add Roles and Features task from the Manage menu, to display the Add Roles and Features Wizard.
On the Select installation type page, select the Role-based or feature‑based installation option and then click Next.
Select the Web Server (IIS) role in the server core.
Select the Web Server and the Application Development role services.
Check the WebSocket Protocol check box and then click the OK button.