Right now the default classloader JBC uses for deserializing RPC calls is the CL that loads RpcDispatcher. This thread is to discuss if that's the correct choice. Would the TCCL in effect when the cache was deployed be a better option? In the AS, this would likely be the default UCL for the deploy dir. If the cache was specifically deployed as part of an scoped ear or sar or even a webapp, it would be the deployment's CL. The same effect can be achieved by using the region API and registering the deployment CL for region "/", but: 1) That requires programmatic intervention; a simple -service.xml deployment is insufficient. 2) If forces use of VersionAwareMarshaller, i.e. serializing a region Fqn at the head of each RPC call. Extra overhead. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3989418#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...