ZBT-WG3526 Hardware offloading issue

For Developers
1

Hi there, I'm configuring zbt-wg3526 router with OpenWrt 21.0.2 and kernel 5.4.179 onboard everything is fine, except hardware offloading doesn't work at all, though it is turned on.

firewall.@defaults[0].flow_offloading='1'
firewall.@defaults[0].flow_offloading_hw='1'

I made some speedtest with iperf3

root@OpenWrt:~# iperf3 -c 192.168.1.2 -u -l 1472 -b 1000m
warning: UDP block size 1472 exceeds TCP MSS 1448, may result in fragmentation / drops
Connecting to host 192.168.1.2, port 5201
[  5] local 192.168.1.1 port 57478 connected to 192.168.1.2 port 5201
[ ID] Interval           Transfer     Bitrate         Total Datagrams
[  5]   0.00-1.00   sec  17.1 MBytes   143 Mbits/sec  12155
[  5]   1.00-2.00   sec  15.8 MBytes   132 Mbits/sec  11251
[  5]   2.00-3.00   sec  15.5 MBytes   130 Mbits/sec  11026
[  5]   3.00-4.00   sec  15.3 MBytes   129 Mbits/sec  10926
[  5]   4.00-5.00   sec  15.3 MBytes   129 Mbits/sec  10926
[  5]   5.00-6.00   sec  15.3 MBytes   128 Mbits/sec  10907
[  5]   6.00-7.00   sec  15.3 MBytes   129 Mbits/sec  10912
[  5]   7.00-8.00   sec  15.3 MBytes   128 Mbits/sec  10909
[  5]   8.00-9.00   sec  15.3 MBytes   129 Mbits/sec  10913
[  5]   9.00-10.00  sec  15.3 MBytes   129 Mbits/sec  10921
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Jitter    Lost/Total Datagrams
[  5]   0.00-10.00  sec   156 MBytes   131 Mbits/sec  0.000 ms  0/110846 (0%)  sender
[  5]   0.00-10.00  sec   156 MBytes   131 Mbits/sec  0.044 ms  0/110846 (0%)  receiver

iperf Done.
root@OpenWrt:~# iperf3 -c 192.168.1.2 -u -l 47 -b 1000m
Connecting to host 192.168.1.2, port 5201
[  5] local 192.168.1.1 port 58962 connected to 192.168.1.2 port 5201
[ ID] Interval           Transfer     Bitrate         Total Datagrams
[  5]   0.00-1.00   sec   557 KBytes  4.56 Mbits/sec  12137
[  5]   1.00-2.00   sec   541 KBytes  4.43 Mbits/sec  11790
[  5]   2.00-3.00   sec   543 KBytes  4.45 Mbits/sec  11838
[  5]   3.00-4.00   sec   543 KBytes  4.45 Mbits/sec  11832
[  5]   4.00-5.00   sec   542 KBytes  4.44 Mbits/sec  11813
[  5]   5.00-6.00   sec   542 KBytes  4.44 Mbits/sec  11810
[  5]   6.00-7.00   sec   544 KBytes  4.45 Mbits/sec  11848
[  5]   7.00-8.00   sec   546 KBytes  4.47 Mbits/sec  11890
[  5]   8.00-9.00   sec   544 KBytes  4.45 Mbits/sec  11844
[  5]   9.00-10.00  sec   543 KBytes  4.44 Mbits/sec  11820
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Jitter    Lost/Total Datagrams
[  5]   0.00-10.00  sec  5.32 MBytes  4.46 Mbits/sec  0.000 ms  0/118622 (0%)  sender
[  5]   0.00-10.00  sec  5.32 MBytes  4.46 Mbits/sec  0.028 ms  0/118622 (0%)  receiver

iperf Done.

CPU is MT7621 (mipsel_24kc)

2

Are you sure the offloading actually helps with non routed traffic?

3

I guess there should no difference between routed and non-routed traffic, cause ASIC should process internetworking, not CPU, like in my case.

4

To get real throughput performance run iperf on a separate device - not the router itself.

Unless you’re use case is for the router to be an endpoint (client or server).

Offloading won’t offload traffic going to or from your router.

5

Hm, interesting, gonna check it