No, you can run either VidiReports or VidiCube without any connection, and collect the data later. Actually, because the collected data is only metadata, it only makes for some 200Kb per day, which could easily be stored on a local disk without running the risk of disk saturation.

However, we recommend a live connection that will collect data along the way and let you monitor that everything works fine, with alerts being sent in case of anomaly.