RAD functions completely in user space. The Pattern Matter (PM) module of the CMI looks up for URLs in the cache and if not found, contact the RAD process in user space to do online categorization

RAD is completely loaded as a kernel module that looks up URL in cache and if not found connects online for categorization. There is no user space involvement in this process

RAD is not a separate module, it is an integrated function of the 'fw' kernel module and does all operations in the kernel space

RAD has a kernel module that looks up the kernel cache, notifies client about hits and misses and forwards a-sync requests to RAD user space module which is responsible for online categorization