You've destroyed an important bit of information in your paraphrasing. The literal quote: > It turned out that on some connections, about every fifth packet we

You've destroyed an important bit of information in your paraphrasing. The literal quote: > It turned out that on some connections, about every fifth packet we sent would just disappear into the Ethernet. Due to the way packet-queueing works, it is actually a reasonable failure-expectation. If the network is on the edge of congestion, a packet will be dropped as there's no space in the queue, but another packet will be sent and clear space in the queue before a second packet has a chance to be lost. In many near-congestion failure modes, it is literally every fifth or tenth or twentieth packet that gets dropped. This is actually the basis of how TCP's congestion-control works, too.