Expertise, for performing classification of a type of network traffic, can be encapsulated in a module. A set of modules, as currently available to a traffic controller, can be referred to as a collection. An improved process, for updating a collection of modules, is presented. A traffic controller can have two or more locations, each storing a module collection. While an old collection remains active, a new collection can be loaded. Once the new collection is loaded, transitioning can be undertaken, on a session-by-session basis that keeps a traffic controller active, from the old collection to the new collection.