•The global queue, which is managed by the process that runs ASP.NET (Aspnet_wp). The global queue is configured in the Machine.config file by the
•The application queue, or virtual directory queue, which is managed by the HttpRuntime class. The HttpRuntime class provides run-time services for ASP.NET applications. There is one queue for each virtual directory. The application queue is configured in Machine.config by the
When either queue exceeds its default limit, the request is rejected with a 503 error (Service Unavailable).