TCP-Eifel does not touch congestion control but improves TCP performance through enhancing its
error control. By the way, "the Eifel" is the name of a beautiful mountain range in Western Germany :-)

TCP-Eifel has the following three new features:

1.  The Eifel Algorithm
2. The Eifel Retransmission Timer
3. “Retransmit Forever”
The current version of TCP-Eifel for FreeBSD is 1.1. It was implemented by Reiner Ludwig in the context of 
the ICEBERG Project. A patchfile for FreeBSD 3.2 is available here.

Things left to do:

Please report bugs and suggestions to Reiner Ludwig ( and
Keith Sklower ( who greatly supported the implementation and testing work.
Last updated 08/17/2000.