performance tuning for adsl and rfc1337

Hi everyone, While reading the DSL howto to see if there is anything I can do for tuning the performance of my ADSL connection I found thru using sysctl to change the following value net.ipv4.tcp_rfc1337 = 1 currently this value is 0 with the SuSE precompiled kernel 2.2.18. I read the rfc 1337 document and it sounds martian to me. In plain english can someone explain what does it mean and what do I gain/loose by changing the above parameter to 1 TIA -- Togan Muftuoglu