This post is to show and describe the 4 tenets of SOA and how is it implemented in WCF Technology in a way,how can WCF to avoid the wellknown pitfalls of using current technologies such as (WSE):
1) Boundaries are explicit :
Applications is communicating to each other by sending and receiving messages to each other.
2) Services are autonomous: you can't control any service out of your organization boundaries.
Your solution should be loosly coupled ,so it can tolerate these changes and continue running if one or more services are un available.
3) Services share schema,contracts not classes or types: simply each service publish the schema of the data which will be exchanged between the service and clients and how can be binded to the clients,these information is used by clients to consume the published services.
4)Compatability is based on policy:Schemas and contracts exposed by the service is define the "Shape" of the service.
if you familiar with WS Enhancements,it has its specification on WS-Security,WS-Interoperability....etc which has been encapsulted into the WCF unified platform.
From Introducing WCF- MS Press