The internet connects countries and continents primarily through submarine fiber optic cables that run under oceans. These high-capacity cables transmit data using light signals, enabling global communication. This complex engineering process involves advanced technology and careful planning to ensure global fiber internet connectivity. ” Physical glass cables on the ocean floor carry the bulk of intercontinental traffic—which is why chokepoints and cable cuts can slow (or sometimes partially disrupt) entire regions. Structure of Undersea Cables 1. From how light pulses travel inside.