Clemens Vasters gave a great talk on WCF today concerning binding and contracts; I got a lot out of it even though a lot was review, but it was good review because it solidified a lot of things that were nebulous to me still. Here are some basic notes:

1. There are three basic types of contracts
1. Service: which concerns the ports, operations and behaviors.
2. Data: data types,
3. Message: which define the format of the message on the wire.
2. There are three ways to talk:
1. One way: send the message and "forget" about it,
2. Request/Reply: where there is a request .... wait ..... response model,
3. Duplex: most easily thought about in terms of "callbacks"
3. One way requests are important because they're effecient. If the protocol is reliable that it's being sent on, you don't ahve to worry about it not getting there...you can send the message and forget about it. This is a good choice for several solutions.
4. Duplex is back channel, callback based.
5. Take note of "Channel Builder",
6. You can declare the back channel as [OperationContract(IsOneWay=True )]
7. Take note of "Dispatcher"
8. Duplex: [ServiceContract(Session=true), CallbackContract=typeof(IMYCALLBACKTYPE)]. The IMYCALLBACKTYPE is the interface the client is going to be using to reach the methods to call back.
9. Fault tolerance:
1. [FaultContract(typeof(SOMETYPE))] .....
2. ......
3. throw new FaultException<SOMETYPE>
1. These things are handled as soap exceptions
10. If you wish to work on the actual XML format, use the XMLSerializer
11. Bindings:
1. BasicHTTPBinding: "Old style"
2. WSHTTPBinding: "New style". Secure, reliable.
3. NetTCPBinding: Becoming very fast, almost as fast as COM+/DCOM. Instant firewall feedback/ NAT feedback.
4. NetNamedPipeBinding: maximum performance, same machine, on windows.
5. NetMSMQBinding: robust, reliable, queue-based transport.
6. MSMQIntegrationBinding: integration with old-style MSMQ applications.
7. NetPeerTCPBinding: for building peer to peer meshes.

The remainder of his talk was very informative, but difficult to express here as he went through particular case scenarios. This was an excellent way of seeing these protocols actually walk and therefore very a very expressive way of showing how to use the various binding types and why.