This document provides an overview of ASP.NET SignalR, a library for building real-time web functionality. It discusses traditional web application approaches using request-response, defines what "real-time" means in terms of pushing data from server to client. It introduces SignalR as a library that uses push technology to provide persistent connections and real-time functionality. It also covers SignalR's transport techniques including websockets, server-sent events, forever frames, and long polling, as well as the types of connections in SignalR including persistent connections and hubs.

1. ASP.NET
SignalR

2. Topics Focused On!!!
• Traditional Web Approach
• What does “Real Time” mean?
• SignalR – “The Rockstar”
• Quick Glance at - Transport Techniques
• Types of Connections
• How do I get SignalR?
• Demo

3. Traditional Web Approach
Sends a Request to the Server – (Step 1)
[In other words, the Client is trying to
pull some information from the Server]
SERVER
CLIENT
Response Sent back to the Client – (Step 3)
Processes
the Request
(Step 2)

4. Real Time Web Applications

5. What is Real Time Web Application?
• In simple terms, “Real Time” means an immediate response
being sent by the Server to the Client.
• Real Time is all about “Pushing” instead of “Pulling”
• Push Technology is completely different from Pull
Technology. Its about getting told what’s new, instead of
asking for what’s new!!!
• Facebook, Twitter, Yahoo Cricket Live, Stock Ticker

6. Real Time Web Approach
User Sends a Request to the Server
CLIENT Creates a Persistent Connection between them
SERVER
Response Sent back to the Client
Response Sent back to the Client
Response Sent back to the Client

7. SignalR – The Rockstar
• SignalR is an asynchronous library. Used to develop Real Time
Web Application.
• Concept intiated by “David Fowler” and “Damien Edwards”
• Provides Client to Server persistent connection over HTTP.
• Makes use of Push Technology.
• Provides Abstraction over the set of transports.
• Open Source available on Github!!!

8. SignalR
Transport Connections
Techniques

9. Transport Priority
WebSockets
Server-Sent events
Forever Frame (IE hack)
Long Polling

10. WebSocket
• A new transport technique which came up with HTML5.
• It internally works on top of TCP protocol.
Pros Cons
Full-duplex persistent Supported only on latest
connection (both ways) browsers – (IE 10)
Fastest solution Works only with IIS-8.0

11. Server Sent Events
• Requires a single connection between Client-Server.
• Uses Javascript API – “EventSource” through which Client can
request a particular URL to receive data stream.
• Used to send Message Notifications or Continuous Data Streams.
Pros Cons
No need to reconnect Works in server-to-client
direction only
Not supported in IE

12. Forever Frames
• Data is sent out in chunks.
• Internally creates an Iframe along with a script on the page to
fetch the data.
Pros Cons
Supported on IE Browser. Iframes are loaded again
and again with chunks of
data.
All script tags remain on the
page

13. Long Polling
Server
Response
Request
Variable delay Client
Time: requests event ‘n’ seconds (variable)

14. SignalR Connections
Hubs
Persistent Connection

15. Persistent Connection
• Provides a raw / low-level control to manage connection.
• Contain events like
“OnConnection”, “OnDisconnection”, “OnReconnection”
• We can write our own logic in these events.

16. Hubs
• Provides a High-level API.
• Client calling Server.
• Server calling Clients. (All, Groups, One).
• Broadcasting messages to all connected clients.
• Works in a similar way like a “Controller”

17. How do I get SignalR?

21. Some References!!!
Some JQuery!!!

22. Routing is Very Important!!!

23. Server Calling Client

24. Client Calling Server Function

25. DEMO

26. Thanks for Listening!!!