I've got 2 6.0 systems: one in BOS one in LA. Transit time is about 100ms. There's adequate bandwidth end-to-end.
I can only get 1.5 - 2.5 MB/sec due to the long fat pipe problem: the receiving system won't open the window large enough to let the sender put enough bytes in the pipe. It's not congestion or starvation on either end or in the middle. I can open multiple streams and get at least 1 MB/sec more for each one opened. Summarized and trimmed this is what tcpdump shows: 0.129225 BOS -> LA 1448 timestamp 1082831729 1595875102 0.129471 BOS -> LA 1448 timestamp 1082831729 1595875102 0.129721 BOS -> LA 1448 timestamp 1082831729 1595875102 0.133218 LA -> BOS win 17014 ts 1595875102 1082731729 0.133218 LA -> BOS win 16652 ts 1595875102 1082731729 0.133218 LA -> BOS win 16290 ts 1595875102 1082731729 0.133218 LA -> BOS win 15928 ts 1595875102 1082731729 0.133218 LA -> BOS win 17376 ts 1595875102 1082731729 0.133558 ... 0.135478 9 packets of 1448 0.136721 ... 0.136791 3 acks 18825, 21721, 21721 0.137081 ... 0.137220 4 packets of 1448 etc. In the bad old days I'd crank tcp.recvspace up to 200000 or so and get at least 5x bandwidth. What can I tune? I'll gladly patch & recompile. snd_sshthresh? thanks Geoff Steckel
