A: 

when you pass an instance of com.myclientcompany.server.eai.interactionspecimpl as argument to your ejb. the weblogic needs to deserialize(unmarshal) the object under the ejb context, and its needs the required class for unmarshalling. so if you include the interactionspecimpl class in your ejb-jar file, then you do not need to include those classes in your servers classpath

sagar