
CPU Twinhead Subnote(486 33MHz)
OS BSD/OS V2.0.1
Router SPARCstation10(SunOS4.1.3)
TCP Buffer Size 8196byte (8196octet)
(Maxmum Window Size) 16384byte (16384octet)
32768byte (32768octet)
65535byte (66535octet)
131072byte (131072octet)
196608byte (196608octet)
246723byte (246723octet)
Message Size 1024byte
Start Time 0.00s
Number of Send 1000

You can see TCP Slow-Start functions really slow when it is transfered on the long-delay satellite link.

It seems that TCP Window Scale option works well on the long-delay satellite link. But 7~8 seconds are need to achive maximum throughput.

If your ftp uses window size under 8192byte, you can transfer files only under about 100kbps on satellite link whose round trip time is about 0.5 seconds.
