SignalR provides API for building real time web functionality in the ASP.NET applications. Real Time web functionality is the ability to have server side code push content to the connected clients as it happens in real time.
The most common examples of real time web applications are Facebook’s news feed and Twitter, or features like chat and search, where the user gets the notification in the browser’s document window as the event happens in the form of a message, alert, update, or link to an article with decreased server load time.
In comparison, the Comet web application model will support an HTTP request that is held open for a long period of time during which time the server can send data to the client without the client knowing it may need to request it. For Internet Explorer, the Forever Frame, which creates a hidden iFrame that opens a connection that acts as a one-way connection from the server to the client. To get back the other way, from client back to server, a standard HTML request is posted and a new connection must be created per data packet to be sent. For other browsers, Ajax is implemented to poll the server with a request that stays open until the server responds and closes the connection, instantiating a request to open another connection.
Monitoring how your packets are transported can positively or negatively impact your code reception by users accessing and using your real-time web environments through browsers. The most successful real-time web environments were able to adeptly anticipate and implement their users’ propensities and seamlessly integrate those practices to create a true real-time web environment that can be accessed from anywhere with any device.