ure0: Questionable Performance

[matthewd%fastmail.us@localhost]

Hi,

May I have some help troubleshooting poor network performance?  I have an older laptop (Thinkpad 13) with a USB-C Ethernet dongle that attaches as ure0 as it has no builtin Ethernet port.  I'm running  NetBSD 10.0 STABLE built locally from a couple of days ago.

$ uname -a
NetBSD snoopy 10.0_STABLE NetBSD 10.0_STABLE (GENERIC) #2: Sun Jul 21 02:18:18 MDT 2024  sysbuild@snoopy:/home/sysbuild/amd64/obj/usr/src/sys/arch/amd64/compile/GENERIC amd64

$ grep ure0 dmesg
[     4.005001] ure0 at uhub0 port 4
[     4.034998] ure0: Realtek (0x0bda) USB 10/100/1000 LAN (0x8153), rev 3.00/30.00, addr 6
[     4.064998] ure0: RTL8153 ver 5c20
[     4.174998] rgephy0 at ure0 phy 0: RTL8251 1000BASE-T media interface, rev. 0
[     4.234998] ure0: Ethernet address 9c:eb:e8:54:53:73

$ grep uhub0 dmesg
[     1.989710] uhub0 at usb0: NetBSD (0x0000) xHCI root hub (0x0000), class 9/0, rev 3.00/1.00, addr 0
[     2.024993] uhub0: 6 ports with 6 removable, self powered
[     2.614995] umass0 at uhub0 port 2 configuration 1 interface 0
[     3.185000] uhub3 at uhub0 port 3: Generic (0x0bda) 4-Port USB 3.0 Hub (0x0411), class 9/0, rev 3.00/1.17, addr 3
[     4.005001] ure0 at uhub0 port 4

$ grep usb0 dmesg
[     1.026529] usb0 at xhci0: USB revision 3.0
[     1.989710] uhub0 at usb0: NetBSD (0x0000) xHCI root hub (0x0000), class 9/0, rev 3.00/1.00, addr 0

$ ifconfig ure0
ure0: flags=0x8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        capabilities=0x3ff00<IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx,TCP4CSUM_Tx>
        capabilities=0x3ff00<UDP4CSUM_Rx,UDP4CSUM_Tx,TCP6CSUM_Rx,TCP6CSUM_Tx>
        capabilities=0x3ff00<UDP6CSUM_Rx,UDP6CSUM_Tx>
        enabled=0
        ec_capabilities=0x1<VLAN_MTU>
        ec_enabled=0
        address: 9c:eb:e8:54:53:73
        media: Ethernet autoselect (1000baseT full-duplex)
        status: active
        inet6 fe80::e15f:2812:3ff7:850%ure0/64 flags 0 scopeid 0x2
        inet6 2600:6c67:697f:6a77:9d2f:6b1:2c56:2ed7/64 flags 0x40<AUTOCONF>
        inet6 fdb7:2fef:8e0e:0:e9f1:a99d:c75e:8052/64 flags 0x40<AUTOCONF>
        inet6 2600:6c67:697f:6a77::5b3/128 flags 0
        inet6 fdb7:2fef:8e0e::5b3/128 flags 0
        inet 192.168.1.121/24 broadcast 192.168.1.255 flags 0

However, using iperf3 to measure networking performance, it seems a bit substandard:

$ iperf3 -c 192.168.1.131
Connecting to host 192.168.1.131, port 5201
[  5] local 192.168.1.121 port 62544 connected to 192.168.1.131 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.01   sec  5.75 MBytes  47.8 Mbits/sec    0   3.00 MBytes       
[  5]   1.01-2.02   sec  5.50 MBytes  45.7 Mbits/sec    0   3.00 MBytes       
[  5]   2.02-3.02   sec  5.50 MBytes  46.1 Mbits/sec    0   3.00 MBytes       
[  5]   3.02-4.02   sec  5.50 MBytes  46.1 Mbits/sec    0   3.00 MBytes       
[  5]   4.02-5.02   sec  5.62 MBytes  47.2 Mbits/sec    0   3.00 MBytes       
[  5]   5.02-6.02   sec  5.50 MBytes  46.1 Mbits/sec    0   3.00 MBytes       
[  5]   6.02-7.02   sec  5.50 MBytes  46.1 Mbits/sec    0   3.00 MBytes       
[  5]   7.02-8.02   sec  5.50 MBytes  46.1 Mbits/sec    0   3.00 MBytes       
[  5]   8.02-9.02   sec  5.50 MBytes  46.1 Mbits/sec    0   3.00 MBytes       
[  5]   9.02-10.02  sec  5.50 MBytes  46.1 Mbits/sec    0   3.00 MBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.02  sec  55.4 MBytes  46.4 Mbits/sec    0             sender
[  5]   0.00-10.24  sec  55.5 MBytes  45.4 Mbits/sec                  receiver

Is this an artifact of the driver, the USB system, or a misconfiguration on my end ?  
Swapping network cables with a desktop linux system which sees 351 Mbit/sec via the same iperf3 does not change the numbers significantly.  So, I think I can rule out a bad cable...

Any tips appreciated!

-Matthew
-- 
  
  matthewd%fastmail.us@localhost