A method for verifying interconnection of a power sourcing equipment,PSE, and a powered device,PD, with 4 pair power over Ethernet,PoE, capabilities using the PSE, comprising: performing a first classification event on a first plurality of twisted pairs (A and B) and detecting a first predetermined class current on the first twisted pairs (A and B) in response to the first classification event; performing the first classification event on a second plurality of twisted pairs (C and D) and detecting the first predetermined class current on the second twisted pairs (C and D) in response to the first classification event; performing a second classification event on the first twisted pairs (A and B) and detecting the first predetermined class current on the first twisted pairs (A and B) in response to the second classification event; performing the second classification event on the second twisted pairs (C and D) and detecting a second predetermined class current on the second twisted pairs (C and D) in response to the second classification event, wherein the second predetermined class current is different than the first predetermined class current; assigning a first pseudo-random variable to the PSE; after expiration of a first variable delay period that is related to the first pseudo-random variable, performing a third classification event on the first twisted pairs (A and B) and detecting a first derived class current on the first twisted pairs (A and B) in response to the third classification event; and after expiration of a second variable delay period that is related to a second pseudo-random variable assigned to the PD, performing the third classification event on the second twisted pairs (C and D) and detecting a second derived class current on the second twisted pairs (C and D) in response to the third classification event performing a first classification event on a first plurality of twisted pairs (A and B) and detecting a first predetermined class current on the first twisted pairs (A and B) in response to the first classification event; performing the first classification event on a second plurality of twisted pairs (C and D) and detecting the first predetermined class current on the second twisted pairs (C and D) in response to the first classification event; performing a second classification event on the first twisted pairs (A and B) and detecting the first predetermined class current on the first twisted pairs (A and B) in response to the second classification event; performing the second classification event on the second twisted pairs (C and D) and detecting a second predetermined class current on the second twisted pairs (C and D) in response to the second classification event, wherein the second predetermined class current is different than the first predetermined class current; assigning a first pseudo-random variable to the PSE; after expiration of a first variable delay period that is related to the first pseudo-random variable, performing a third classification event on the first twisted pairs (A and B) and detecting a first derived class current on the first twisted pairs (A and B) in response to the third classification event; and after expiration of a second variable delay period that is related to a second pseudo-random variable assigned to the PD, performing the third classification event on the second twisted pairs (C and D) and detecting a second derived class current on the second twisted pairs (C and D) in response to the third classification event