As far as I understand the partnumber,
the 1628 would be an 10/100 Base-T Single Port Transformer and
the 2018 would be an 10/100 Base-T Dual Port Transformer
You know, I haven't removed them yet, they're SMD and I hate that crap with my caveman melty stick, I'm liable to incinerate it. But actually who cares I'll give it a shot. My SMD LED mortality rate is like 50% heh
but man hang on transformers?! little tiny transformer? I'll get you pin count but what (ballpark) kinda voltage are we talking for these? That's.... neat...... little transformers?!