The key piece of equipment that might have brought down Optus

On Wednesday, Optus chief executive Kelly Bayer Rosmarin said it was too "technical" to explain what happened, but the company would offer a full explanation once it got to the root cause of the issue. In a statement on Thursday, Optus said: "In common with major global telecommunication networks, the Optus network is designed with multiple layers of fallback and redundancy. At the heart of this is a modern intelligent router network developed with the world's leading vendors. "Despite this, a network event yesterday triggered a cascading failure which resulted in the shutdown of services to our customers," Optus said,…