On Sat, 26 Dec 2020, Baldur Norddahl wrote:
It is true there have been TCP improvements but you can very easily verify
for yourself that it is very hard to get anywhere near 1 Gbps of actual
transfer speed to destinations just 10 ms away. Try the nlnog ring network
like this:
gigabit@gigabit01:~$ iperf -c netnod01.ring.nlnog.net
------------------------------------------------------------
Client connecting to netnod01.ring.nlnog.net, TCP port 5001
TCP window size: 85.0 KByte (default)
------------------------------------------------------------
[ 3] local 185.24.168.23 port 50632 connected with 185.42.136.5 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 452 MBytes 379 Mbits/sec
Why would you just use 85KB of TCP window size?
That's not the problem of buffering (or lack thereof) along the path, that
just not enough TCP window size for long-RTT high speed transfers.
--
Mikael Abrahamsson email: swm...@swm.pp.se
