RIAs delivered faster with CDN
In a traditional server centric architecture UI is built on the server via php scripts, jsp or asp. So the UI is built and all that html travels back to the browser over the network. Ajax reduces this traffic by updating portions of pages on the browser. CDN benefits these architectures in 2 ways:
1) Delivering static content from an edge server
2) IP route optimization - like a dedicated network pipe between the client browser and the server (may not be complete end to end but a large part of the network pipe) provided by the CDN provider. So IP packet loss should be lower leading to better latency.
When it comes to full blown RIAs with complete client side UI frameworks - GWT or Flex (there are quite a few complete client side JS frameworks - have used GWT and Flex and listing here) the entire network traffic after the client is downloaded is limited to just data transfer requests. Static content becomes more either in the form of Flex modules or the huge JS framework files. So point 1) above becomes more critical to RIAs. Point 2) - route optimization can still deliver benefits but as the traffic is just data (should be roughly about 20% of a complete html UI) the benefits are much less. In our deployment (Flex + Java backend) a server request typically lasts about 20ms on the server on a 32MB tomcat. The largest response size goes to about 8K after compression (we compress data as it mostly xml).
