Better known for its security services, VeriSign also operates a switching system that directs 26 billion transactions per day. Every call for a .com or .net domain passes through the system.
The current capacity of those root servers is around 400 billion, according to this Washington Post piece. Those numbers may sound like they provide plenty of wiggle room, but traffic demands are increasing at such a pace that we're really too close for comfort.
VeriSign will invest, over three years, some $100 million in the switching infrastructure to reach a full capacity of 4 trillion transactions daily.
The investment will also cover security upgrades, says Forbes -- front of mind for many after this week's reports of significant attacks on several root servers (not VeriSign's, reportedly).