This document discusses how Web Sockets can be used beyond web browsers. It begins with an introduction to Web Sockets and how they solve the request-response dilemma by allowing full-duplex communication. The document then demonstrates how Web Sockets can be implemented in WCF services to allow communication from non-browser clients like WPF and Windows 8 applications. Code samples and slides from the presentation are provided at the end.

1. Web Sockets are not
Just for Web Browsers
September 2013

2. About Me
 I am a software developer, based out of Phoenix, Arizona, that specializes in
.NET technology.
 Expert on just about all areas of MS.NET programming, but focused on, but
not limited to
 Connected Systems Technologies
 Windows Communication Foundation (WCF)
 BizTalk
 Windows Workflow Foundation (WF)
 SQL Server
 Senior Consultant for Neudesic, LLC
 President of Phoenix Connected Systems User Group

3. What the Heck
are they?
Web Sockets
Overview
We got a problem
Dilemmas With Traditional Methods Ladies and
Gents, We Have
a Solution
Solving the request response
dilemma
Where are the 1s and 0s:
Code Bits and Demonstration
Meat of the
Presentation:
Web Sockets beyond web
browsers
Wrap it Up
Already!
Conclusion, Questions
and Answers
But Why?:
Why Use Web Sockets Beyond
Web Browsers
3
1
2

4. What are Web Sockets?
 Web Sockets are a standard created by the
W3C as developed as a part of the HTML5
initiative
 RFC 6455 defines constraints for a protocol
 Bi-directional session-ful communication
between client and server
 Beats old school polling conventions
 Request Response Dilemma
 API for using Web Sockets

5. Key Take-Aways
Is it request response? Nope. It‟s Full duplex.
More on this later…

6. What Else?
Solves world hunger!!!!
…
Well, not really, but it‟s still pretty awesome

7. We Got a Problem Here:
Request / Response Dilemma
Request: I need „XYZ‟ resource
Response: Here is „XYZ‟ resource
Client Server

8. JavaScript Solutions
 How do we circumvent the fact that we can‟t receive events on the client
from the server?
 JavaScript polling
 Short Polling
 Client checks every so often for events and messages that the server has queued
 Long Polling
 Client makes 60 – 120 second connections to the server and waits for events during that
time
 If no events are received, the server closes the session
 Rinse and repeat

9. Short Polling

10. Long Polling

11. I bet you have a question right about
now…
What are we ever to do????

12. Please… let me catch my breath
Don‟t fret. Let me back up a second and catch my breath…

13. Web Sockets: The Solution to the
Request / Response Dilemma
 Web Sockets are full duplex
 Walkthrough of the process:
 Client establishes web socket connection to server
 4 minutes pass
 Server determines that an event needs to be sent to the client
 Event sent through established connection
 Problem solved!!
 Important takeaway: Connection is synchronous (connect > disconnect), but
messages are asynchronous

14. Solution Overview

15. Full duplex!
Full duplex from a web brower???
This is awesome!

16. Full duplex!
However, I won‟t believe it until I see it

17. Show me the code!

18. Web Sockets are not Just for Web
Browsers
 As of version 4.5, .NET WCF supports Web Sockets
 Web Sockets are easily implemented using the netHttpBinding
 Full Duplex services
 Existing service can quickly and easily add a netHttpBinding to the
configuration in order to implement this
 Shortly, I will show you just how that is done

19. You‟re probably wondering…
Wait a second Chris… You‟re telling me that I can use other applications other
than web browsers?

20. The Truth and Nothing but the Truth
Yes my friend. This is the magic of open source protocols.
“How?”, you ask. I‟ll show you how!

21. Show me the code again!

22. The Demo
Web Browser
WPF Client

23. Why Chris?
 Firewall benefits
 Web Sockets supported by most firewalls since the underlying protocol is via HTTP
 OSI Layer 5+ firewalls still support web sockets due to UPGRADE requests
 Platform agnostic protocol
 Protocol defined by W3C and not a single vendor
 Supports Java clients
 Supports .NET clients
 Supports Plethora of Platforms (Python, PHP, Perl)
 Services can be built once
 No more separate solutions for client type restrictions
 One service can support various clients

24. Multiple Clients and One Service
WPF Client
WCF Service
Metro Client
Web Browser
Client

25. Show me the code one last time!
 Demonstrations
 One service
 Windows 8 client
 WPF Client
 Web client walkthrough

26. Code and Slides
• Git Hug: https://github.com/jixer/wcf-windows-8-web-sockets/
• My Blog: http://www.bloggedbychris.com/2013/09/23/nwvdnug-web-sockets-
presentation/

27. PCSUG
 http://pcsug.org/
 Meeting at Interface now
 October 2nd, 2013: The Connected Systems Voyage - Charted and Uncharted
Territories
 Chris Myers, President, PCSUG

28. Questions?