The Aspectix group communication system is the core of the FTflex replication infrastructure. The system uses a generic and flexible architecture on the basis of distributed consensus algorithms. Its configurability allows to seamlessly adjust the system to the environment to provide adequate mechanisms matched to the application's needs.

In addition to crash failures, the system is able to tolerate Byzantine failures of parts of the system as well. This allows tolerating unanticipated erroneous behavior of software and hardware as well as malicious intrusions.