Lack of CDN availability

I use both Telerik and Microsoft CDN, for their respective AJAX toolkits. Both work great 99% of the time. However, I was working out of two different cafes recently and went to visit my site: The first cafe did not permit the Telerik CDN, while the second one does not allow the Microsoft CDN as a URL request. I can actually see the status bar in IE shows "ajax.microsoft.com" as the fil开发者_StackOverflowe being retrieved as I am waiting for the website to load.

Lack of CDN access seems to be a very unusual problem. In fact, I cannot fathom why such URL requests would be blocked when the cafe seems to permit pretty much everything else. Any reason? Could this be an availability issue at the respective CDNs themselves (ie how reliable are these CDNs)? And of-course, is there a recommended fix, apart from discarding CDN use?

Update: I can now connect to my app. So my lack of access to ajax.microsoft.com was most likely a temporary lack of MS CDN availability, and not any domain blocking.

all you need to do is implement fallback to your local server, explained here, http://happyworm.com/blog/2010/01/28/a-simple-and-robust-cdn-failover-for-jquery-14-in-one-line/

The Telerik online demos use the CDN by default, but fallback to embedded resources if the Amazon cloud service is unavailable. If you have the RadControls for ASP.NET AJAX installed locally, then you can see the source of the demo site. The files that you need to review are ~/Common/Footer.ascx and its code file ~/App_Code/QuickStart/Footer.cs, also ~/App_Code/QuickStart/QsfCdnConfigurator.cs ~/App_Code/QuickStart/HeadTag.cs. The Footer files set a cookie using JavaScript, depending on whether the CDN is available and the last two files provide support for reading the cookie on the server side and setting the appropriate configuration for the script manager.