Modernizing the En Route system presents major acquisition issues to the Federal Aviation Administration (FAA). At the present time, efforts are underway to upgrade the En Route system, primarily focusing on the host computer system. This report addresses the use of different technologies and an architectural tradeoff approach on a typical En Route system problem. We were requested to consider the problem of resectorization, i.e., the combination and decombination of sectors (and fix posting areas) during operation of the En Route center. Such capabilities may become desirable for an implementation of free flight. Two technologies have been applied to develop solutions to this problem, namely Common Object Request Broker Architecture (CORBA) and POSIX.21 (Portable Operating System Interface Standard). The former is based on an object-oriented model, while the latter is based on a message-passing model.