title: Best way to implement an ACL on an ESB
body: <p>I am currently trying to implement an ACL on an ESB (Camel apps on Servicemix) which will enable each service artifact to decide if current user is a valid user and if it has required priviledge to access the service. I have decided to use the RBAC (Please, kindly recommend if there are superior models) model. My actual headache is how to implement the model, service call vs in memory. 
  Making a network service call for each verification/authentication is definately too much for this as the ACL server (Which has the business logic) will be implement as a service to other artifacts for re-usability. The alternate is to implement locally and verify from database or memory. What are the popular ways this type of problems are being solved?</p>