How to Quicken TCP Re-transmission?

[mag at intron.ac]

Hi,
     I want to transmit data between host A and host B. The link between
these two hosts is really bad: PING reports 30% packet loss and about
60 ms return delay. This means if timed out for 1 second, the data must
have been lost.
     I keep "net.inet.tcp.rexmit_min" and "net.inet.tcp.rexmit_slop"
untouched. But TCPDUMP tells me that if some data are lost,
re-transmission will be done 64 seconds after last transmission!
     How to quicken TCP re-transmission?
     How to tune "net.inet.tcp.rexmit_min" and "net.inet.tcp.rexmit_slop"?
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                                                From Beijing, China