What is the practical difference between transport and message reliability in WCF?

Question

I am looking at differences between using WPF in .NET or using Silverlight 4 for the GUI front end of an app that connects to WCF services.

I have read that net.tcp binding in Silverlight 4 only supports transport level reliability. With a WPF desktop app we can use message level reliability.

What is the actual difference? If transport level reliability ensures that all TCP packets get through, doesnt that also mean that all WCF SOAP messages will also get through?

Answer 1

"Transport reliability is not resilient to dropping network connections and a variety of other communication problems, whereas message reliability, as the name implies, deals with reliability at the message level independent of how many packets are required to deliver the message."

• "WCF Essentials—Reliability", on C# Online.NET
• Thread: "Why not using UDP as a first class binding (NetUdpBinding) in WCF?"

I hope this helps.