This document discusses different approaches for building real-time web functionality and introduces SignalR as a solution. It describes how earlier approaches like periodic pooling and long polling have disadvantages. Web sockets are ideal but have limitations in support across browsers, proxies, and web servers. SignalR abstracts these transports to provide a simple and robust library for adding real-time functionality to ASP.NET applications without these constraints. The document demonstrates SignalR and provides resources to learn more.

1. MICROSOFT DEVELOPER PHILIPPINES TECHNICAL SHARING
SIGNALR
101 Patrick Oliveros
Microsoft MVP ASP.NET/IIS

2. The web evolved
Event-based, real-time UI
Partial page updates (Ajax), RIA
Dynamic pages, forms
Static HTML pages

3. Scenarios

4. Implementations
Periodic Pooling
Long Polling
Server-Sent Events
Web Sockets

5. Periodic Pooling
Polling interval
Cons:
• Poll from time to time using Ajax
• Delay in communications due to polling interval
• Wastes bandwidth & latency 

6. Long Pooling
Cons:
• Poll but don’t respond untill there’s data
• Poll again after data received or after the connection times out
• Consumes server threads & connection resources 

7. Web Sockets (HTML 5)
• Extension to HTTP
• Provide raw sockets over HTTP
• Full-duplex
• Traverses proxies
• It’s still a draft…
• Not every proxy server supports it 
• Not every webserver supports it 
• Not every browser supports it 
• They are raw sockets!

8. So What Now?
Superman SignalR to the rescue!

9. Enter SignalR
• ASP.NET SignalR is a new library for ASP.NET developer that makes it incredibly
simple to add real-time web functionality to your applications
• Async signaling library for .NET to help build real-time, multi-user interactive web
applications ( aka persistent connection abstraction for .NET);

10. Enter SignalR

11. Transport Priority
Web Sockets
Server-Sent Events
Forever Frame
Long Polling

12. Demo

13. Resources
• SignalR project page:
http://www.signalr.net
• SignalR on github:
https://github.com/SignalR/SignalR

14. Thanks!