As an alternative to Periodic Refresh, the response now arrives by Streaming HTTP. A long-lived XMLHttpRequest Call occurs, and service continues to output new messages as they arrive. Meanwhile, the browser polls the full response, and checks if a new message has been added since the last poll. A new request is periodically issued to prevent leaks, timeouts, etc. This pattern is ideally suited to an intranet where you have better control and understanding and control over the network and end-user browsers.