Date: Mon, 9 Oct 2017 22:29:14 +1300 From: Rouan Lucas van Ryn <rvan@SDF.ORG> To: freebsd-wireless@freebsd.org Subject: Wireless network slows down with zyd0 Message-ID: <20171009092914.GA22203@SDF.ORG>
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I have been experiencing slow network speeds with my FreeBSD (11.0)
system on my wireless LAN.
My wireless card is a USB ZyDAS card:
zyd0: <ZyDAS USB2.0 WLAN, rev 2.00/48.10, addr 2> on usbus3
When I start networking, wireless speeds seem OK (~700KB/s when scp'ing
a file to my laptop on the WLAN), but after around 10 seconds of network
activity drop off to become very slow (~70KB/s). Speeds stay slow until
networking is restarted and then pick up again momentarily. Tests with
iperf yield similar results.
I have found that the wireless connection is being renegotiated at lower
and lower speeds:
wlan0: [0c:d6:bd:1a:19:24] AMRR: current rate 72, txcnt=11, retrycnt=17
wlan0: [0c:d6:bd:1a:19:24] AMRR decreasing rate 48 (txcnt=11 retrycnt=17)
wlan0: [0c:d6:bd:1a:19:24] AMRR: current rate 48, txcnt=11, retrycnt=14
wlan0: [0c:d6:bd:1a:19:24] AMRR decreasing rate 36 (txcnt=11 retrycnt=14)
wlan0: [0c:d6:bd:1a:19:24] AMRR: current rate 36, txcnt=11, retrycnt=13
wlan0: [0c:d6:bd:1a:19:24] AMRR decreasing rate 24 (txcnt=11 retrycnt=13)
wlan0: [0c:d6:bd:1a:19:24] AMRR: current rate 24, txcnt=11, retrycnt=11
wlan0: [0c:d6:bd:1a:19:24] AMRR decreasing rate 22 (txcnt=11 retrycnt=11)
wlan0: [0c:d6:bd:1a:19:24] AMRR: current rate 22, txcnt=11, retrycnt=13
wlan0: [0c:d6:bd:1a:19:24] AMRR decreasing rate 18 (txcnt=11 retrycnt=13)
wlan0: [0c:d6:bd:1a:19:24] AMRR: current rate 18, txcnt=11, retrycnt=11
wlan0: [0c:d6:bd:1a:19:24] AMRR decreasing rate 12 (txcnt=11 retrycnt=11)
wlan0: [0c:d6:bd:1a:19:24] AMRR: current rate 12, txcnt=11, retrycnt=12
wlan0: [0c:d6:bd:1a:19:24] AMRR decreasing rate 11 (txcnt=11 retrycnt=12)
wlan0: [0c:d6:bd:1a:19:24] AMRR: current rate 11, txcnt=11, retrycnt=11
wlan0: [0c:d6:bd:1a:19:24] AMRR decreasing rate 4 (txcnt=11 retrycnt=11)
wlan0: [0c:d6:bd:1a:19:24] AMRR: current rate 4, txcnt=11, retrycnt=11
wlan0: [0c:d6:bd:1a:19:24] AMRR decreasing rate 2 (txcnt=11 retrycnt=11)
wlan0: [0c:d6:bd:1a:19:24] AMRR: current rate 2, txcnt=11, retrycnt=11
The same wireless card works well (no slowdown) when connected to a
different computer (not FreeBSD) in the same room, leading me to suspect
that this isn't a hardware or signal strength issue.
Netstat shows that packets are being retransmitted:
tcp:
109179 packets sent
108551 data packets (110570192 bytes)
575 data packets (534156 bytes) retransmitted
6 data packets unnecessarily retransmitted
...
Relevant parts of ifconfig:
zyd0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 2290
ether 00:25:xx:xx:xx:xx
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
media: IEEE 802.11 Wireless Ethernet autoselect mode 11g
status: associated
wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
ether 00:25:xx:xx:xx:xx
inet 192.168.1.6 netmask 0xffffff00 broadcast 192.168.1.255
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
media: IEEE 802.11 Wireless Ethernet DS/1Mbps mode 11g
status: associated
ssid SPARK-XXXX channel 1 (2412 MHz 11g) bssid 0c:d6:bd:1a:19:24
regdomain APAC country NZ authmode WPA2/802.11i privacy ON
deftxkey UNDEF TKIP 2:128-bit txpower 30 bmiss 7 scanvalid 60 bgscan
bgscanintvl 300 bgscanidle 250 roam:rssi 7 roam:rate 5 protmode CTS
roaming MANUAL
Note in particular the line:
media: IEEE 802.11 Wireless Ethernet DS/1Mbps mode 11g
ifconfig wlan0 scan gives me:
SSID/MESH ID BSSID CHAN RATE S:N INT CAPS
SPARK-XXXX 0c:d6:bd:1a:19:24 1 54M -58:-95 100 EP RSN HTCAP WPS WPA
(among other networks)
--
Thanks,
Rouan
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