Auto MDI-X was developed by
Hewlett-Packard engineers Daniel Joseph Dove and Bruce W. Melvin.
[2] A pseudo-random number generator decides whether or not a network port will attach its transmitter, or its receiver to each of the twisted pairs used to auto-negotiate the link.
[3][4]
When two auto MDI-X ports are connected together, which is normal for modern products, the algorithm resolution time is typically < 500 ms. However, a ~1.4 second asynchronous timer is used to resolve the extremely rare case (with a probability of less than 1 in 5×1021) of a loop where each end keeps switching.
[5]