The following link is to an article written by Jim Satterwhite and published in EETimes in April, 2004.  The article suggests that the  "Bob Smith Termination"  universally employed on Ethernet ports is not optimal and proposes an improved process for determining the value of the termination that will result in a better termination. 

This link no longer is active, after all, that was 21 years ago.

 (CommsDesign, "Updating the Bob Smith Termination Technique", Jim Satterwhite, April 30, 2004)

The version submitted to the publisher is available in acrobat pdf form, and, is my opinion, is easier to read.