Ethernet interfacing and magnetic transformer

[varunme]

Ethernet interfacing tutorials tells something about a magnetic transformer
what is it , is it something like max232 level shift in rs232 ?
in what packages does it come ?
How a DIY er can implement this thing into a circuit ?

 

[yura717]

**broken link removed**
**broken link removed**
http://www.mouser.com/catalog/supplier/library/TTIMagneticComponents.pdf

 

[varunme]

can we salvage this thing from modems ?