USB 2.0 is extremely reliable. All data transactions are integrity checked using the very comprehensive CRC32 calculation. Additionally, the USB hardware will retry any packets that fail the integrity check during transfer. This makes the USB bus extremely robust in that it can withstand transient events in the environment (ESD, EMI and other electrical noise, and faulty connection) without breaking the flow in other hardware and software systems. USB also has strict requirements on cabling, PCB routing, and connectors. All of this is done to provide a very controlled electrical environment.