Fuse ESB provides a non-standard mechanism to support asynchronous messaging, known as the Normalized Message Router (NMR), which is loosely based on the NMR defined in the JBI standard. The NMR has the advantage that it spans both the OSGi container and the JBI container. By contrast, the OSGi Event Admin Service, which also provides asynchronous communication between bundles, can only be used within the OSGi container.