Policy Export

Korgan Insurance JSC is an insurance company. The internet link was nearly saturated in the evening, although the working day was over. The day's connection export was handed to you.

Nothing subtle is needed here: this is an arithmetic task. Ordinary office sessions are tens and hundreds of kilobytes. You are after what is orders of magnitude larger, and what share of all outbound traffic it represents.

The records carry time, addresses, port and volume in bytes. The internal network sits in a single range; everything else is external.