Retransmissions in case of 1G speed #67
Description
Hello to all
On my PC I use network 10G card based on tehuti + Marvell MV88X3310
On the 10G everything work fine. But when I connect my PC to another (direct connection) with Intel 82574L I'm getting a lot of retransmission. I use 10G certified cable 2 meter lengths.
On the both PC installed Linux Fedora 38.
Th retransmission quite easy to reproduce with iperf3.
On the Fedora 38 (with 82574L) I'm launching iperf3 server:
iperf3 -s -i 10
On the Fedora 38 (with tehuti) client:
iperf3 -c 192.168.101.73 -i 10 -t 1800
In log of iperf3 client I see a lot of retransmission:
Connecting to host 192.168.101.73, port 5201
[ 5] local 192.168.101.136 port 41950 connected to 192.168.101.73 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-10.00 sec 1.08 GBytes 927 Mbits/sec 16502 59.4 KBytes
[ 5] 10.00-20.00 sec 1.08 GBytes 927 Mbits/sec 17137 63.6 KBytes
[ 5] 20.00-30.00 sec 1.08 GBytes 929 Mbits/sec 16485 60.8 KBytes
[ 5] 30.00-40.00 sec 1.08 GBytes 926 Mbits/sec 17191 52.3 KBytes
Summary problem looks like (in case of 1G connection):
Transferring Tehuti+Marvell - > Intel 82574L: a lot of retransmission
Transferring Intel 82574L -> Tehuti+Marvell: no retransmission
Looks like something wrong in case of transmit data from Tehuti + Marvell to Intel 8254L
Also I have tried other PC (with Fedora 38) and Intel I219-LM with the same result.
On Marvell I have tried 0.3.10 and 0.3.11 firmwares. But on both cases I have retransmissions.
Can anybody share the idea for this behavior? For me is really strange that 10G works ok but 1 G not.