[Voyage-linux] Weirdness - 12 second dropouts every 4 minutes

Edwin Whitelaw (spam-protected)
Mon Nov 21 00:33:12 HKT 2005


All,

We have a two hop backhaul using three WRAP boxes that has been up for 
about 6 weeks.  Throughput with iperf is 18-19mbs consistently.  RSSI 
values are typical as indicated below and the Bit Rate stays at 54M.  
Here's the weirdness.

Exactly every 239 seconds the ath0 interface on Hubbell will drop 
connection for exactly 12 seconds, but only on traffic passing *through* 
the interface.  There are also occasional doprouts at 50 and 189 
increments.  Note that the sum is 239 seconds.

If I ping from NRVU to the Hubbell ath0 IP, it never drops but pings to 
anything on the other side of the interface (Hubbell eth0 or ath1 as 
well as to CRC) experience the interruption.

Simultaneous pings from the CRC end to Hubbell's eth0 or ath1 interface 
show no dropouts while the ping from the NRVU end is interrupted.  
Pinging from CRC *through* the Hubbell ath0 link to NRVU does have the 
same pattern of dropouts as expected.

This backhaul feeds my entire network and the dropout behavior is making 
all interactive sessions extremely unpleasant to unusable.  The 
clockwork regularity of the symptoms lead me to believe there is some 
sort of failure/disconnect/re-association phenomenon occurring but I am 
not able to deduce where.  I have rebooted both NRVU and Hubbell.

Any help/suggestions/solutions will be *very* much appreciated.

Edwin


eth0-CRC-ath0<-/\/\/->ath1-Hubbell-ath0<-/\/\/\/->ath0-NRVU-eth0<---Internal 
network
         CM9   4.6 mi CM9  Master  CM9   3.9 mi   CM9

All three boxes are running Voyage Linux 0.2pre1.  Typical dmesg output 
below:
crc:~# dmesg
Linux version 2.6.8-486-voyage (root at punknix-uml) (gcc version 3.3.5 
(Debian 1:3.3.5-13)) #1 Tue Jul 12 04:06:34 GMT 2005
.
.
.
ath_hal: 0.9.14.9 (AR5210, AR5211, AR5212, RF5111, RF5112, RF2413)
wlan: 0.8.6.0 (EXPERIMENTAL)
ath_rate_onoe: 1.0
ath_pci: 0.9.6.0 (EXPERIMENTAL)
Build date: Jul 12 2005
Debugging version (IEEE80211)
ath0: 11a rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
ath0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
ath0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 
24Mbps 36Mbps 48Mbps 54Mbps
ath0: turboA rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
ath0: turboG rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
ath0: H/W encryption support: WEP AES AES_CCM TKIP
ath0: mac 5.9 phy 4.3 radio 3.6
ath0: Use hw queue 1 for WME_AC_BE traffic
ath0: Use hw queue 0 for WME_AC_BK traffic
ath0: Use hw queue 2 for WME_AC_VI traffic
ath0: Use hw queue 3 for WME_AC_VO traffic
ath0: Use hw queue 8 for CAB traffic
ath0: Use hw queue 9 for beacons
Debugging version (ATH)
ath0: Atheros 5212: mem=0x80000000, irq=12
----end dmesg----

----CRC info------------------
crc:~# ifconfig
ath0      Link encap:Ethernet  HWaddr 00:0B:6B:35:A7:CE
          inet addr:10.220.1.1  Bcast:10.220.1.4  Mask:255.255.255.252

eth0      Link encap:Ethernet  HWaddr 00:0D:B9:01:AC:B4
          inet addr:10.220.202.2  Bcast:10.220.202.255  Mask:255.255.255.0

crc:~# iwconfig ath0
ath0      IEEE 802.11a  ESSID:"crc-hub"
          Mode:Managed  Frequency:5.825 GHz  Access Point: 00:0B:6B:35:C0:4D
          Bit Rate:54 Mb/s   Tx-Power:18 dBm   Sensitivity=0/3
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=25/94  Signal level=-70 dBm  Noise level=-95 dBm
          Rx invalid nwid:1  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:1223  Invalid misc:1223   Missed beacon:190

crc:~# cat /etc/network/interfaces
# Used by ifup(8) and ifdown(8). See the interfaces(5) manpage or
# /usr/share/doc/ifupdown/examples for more information.

auto lo ath0 eth0

iface lo inet loopback

iface ath0 inet static
        address 10.220.1.1
        netmask 255.255.255.252
        broadcast 10.220.1.4
        wireless_essid crc-hub
        wireless_channel 165
#       wireless_rate 36M
        wireless_mode managed
#       wireless_key 313233343536373839307A7863
        up /usr/bin/athctrl -i ath0 -d 10000

#iface eth0 inet dhcp
#

iface eth0 inet static
        address 10.220.202.2
        netmask 255.255.255.0
        broadcast 10.220.202.255
        up route add default gw 10.220.202.1
        up /usr/local/sbin/remountro

crc:~# athstats
190     beacon miss interrupts
940     mib interrupts
274883594       packet sent on the interface
210     tx management frames
3341    tx frames discarded prior to association
80      tx queue stopped because full
1223    tx failed 'cuz too many retries
18352611        long on-chip tx retries
8       tx frames with no ack marked
1348083 tx frames with an alternate rate
2753612 rx failed 'cuz of bad CRC
229032471       packet recv on the interface
92747   periodic calibrations
3       rfgain value change
5565257 rate control checks
316     rate control raised xmit rate
312     rate control dropped xmit rate
rssi of last ack: 30
rssi of last rcv: 22
1       switched default/rx antenna
Antenna profile:
[1] tx 274882575 rx 256398335
[2] tx        2 rx       46

---end CRC info---------


---Hubbell info---------
hubbel:/etc/network# ifconfig
ath0      Link encap:Ethernet  HWaddr 00:0B:6B:34:8A:D9
          inet addr:10.220.2.2  Bcast:10.220.2.4  Mask:255.255.255.252

ath1      Link encap:Ethernet  HWaddr 00:0B:6B:35:C0:4D
          inet addr:10.220.1.2  Bcast:10.220.1.4  Mask:255.255.255.252

eth0      Link encap:Ethernet  HWaddr 00:0D:B9:00:5A:B8
          inet addr:10.220.201.1  Bcast:10.220.201.255  Mask:255.255.255.0

hubbel:/etc/network# iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

ath0      IEEE 802.11a  ESSID:"hub-nrvu"
          Mode:Master  Frequency:5.76 GHz  Access Point: 00:0B:6B:34:8A:D9
          Bit Rate:0 kb/s   Tx-Power:18 dBm   Sensitivity=0/3
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=30/94  Signal level=-65 dBm  Noise level=-95 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:22962  Invalid misc:22962   Missed beacon:0

ath1      IEEE 802.11a  ESSID:"crc-hub"
          Mode:Master  Frequency:5.825 GHz  Access Point: 00:0B:6B:35:C0:4D
          Bit Rate:0 kb/s   Tx-Power:18 dBm   Sensitivity=0/3
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=27/94  Signal level=-68 dBm  Noise level=-95 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:19523  Invalid misc:19523   Missed beacon:0

hubbel:/etc/network# cat interfaces
# Used by ifup(8) and ifdown(8). See the interfaces(5) manpage or
# /usr/share/doc/ifupdown/examples for more information.

auto lo ath1 ath0 eth0

iface lo inet loopback

iface ath1 inet static
        address 10.220.1.2
        netmask 255.255.255.252
        broadcast 10.220.1.4
        wireless_essid crc-hub
        wireless_channel 165
        wireless_mode master
        up /sbin/iwpriv mode 1
        up /usr/bin/athctrl -i ath1 -d 10000


iface ath0 inet static
        address 10.220.2.2
        netmask 255.255.255.252
        broadcast 10.220.2.4
        wireless_essid hub-nrvu
        wireless_channel 152
        wireless_mode master
        up /sbin/iwpriv mode 1
        up /usr/bin/athctrl -i ath0 -d 8000

iface eth0 inet static
        address 10.220.201.1
        netmask 255.255.255.0
        broadcast 10.220.201.255
        up /usr/local/sbin/remountro

hubbel:/etc/network# athstats
252163  packet sent on the interface
6       tx management frames
22962   tx failed 'cuz too many retries
104574  long on-chip tx retries
1007    tx frames with no ack marked
798     tx frames with an alternate rate
890     rx failed 'cuz of bad CRC
222951  packet recv on the interface
10378   rx PHY errors:
    10378 OFDM timing
35251   beacons transmitted
120     periodic calibrations
3611    rate control checks
7       rate control raised xmit rate
5       rate control dropped xmit rate
rssi of last ack: 33
rssi of last rcv: 28
1       switched default/rx antenna
Antenna profile:
[1] tx   228775 rx   222977
[2] tx      431 rx        4

--------end Hubbell info--------

--------NRVU info----------
nrvu:~# ifconfig
ath0      Link encap:Ethernet  HWaddr 00:0B:6B:35:C4:5A
          inet addr:10.220.2.1  Bcast:10.220.2.4  Mask:255.255.255.252

eth0      Link encap:Ethernet  HWaddr 00:0D:B9:02:2F:00
          inet addr:10.220.200.1  Bcast:10.220.200.255  Mask:255.255.255.0

eth0:1    Link encap:Ethernet  HWaddr 00:0D:B9:02:2F:00
          inet addr:204.119.253.225  Bcast:204.119.253.255  
Mask:255.255.255.224

nrvu:~# iwconfig ath0
ath0      IEEE 802.11a  ESSID:"hub-nrvu"
          Mode:Managed  Frequency:5.76 GHz  Access Point: 00:0B:6B:34:8A:D9
          Bit Rate:54 Mb/s   Tx-Power:18 dBm   Sensitivity=0/3
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=29/94  Signal level=-66 dBm  Noise level=-95 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:9148  Invalid misc:9148   Missed beacon:10

nrvu:/etc/network# cat interfaces
# Used by ifup(8) and ifdown(8). See the interfaces(5) manpage or
# /usr/share/doc/ifupdown/examples for more information.

auto lo ath0 eth0 eth0:1

iface lo inet loopback

iface ath0 inet static
        address 10.220.2.1
        netmask 255.255.255.252
        broadcast 10.220.2.4
        wireless_essid hub-nrvu
        wireless_channel 152
        wireless_mode managed
        up /usr/bin/athctrl -iath0 -d8000

iface eth0 inet static
        address 10.220.200.1
        netmask 255.255.255.0
        broadcast 10.220.200.255

iface eth0:1 inet static
        address 204.119.253.225
        netmask 255.255.255.224
        broadcast 204.119.253.255

nrvu:/etc/network# athstats
10      beacon miss interrupts
4       mib interrupts
1350470 packet sent on the interface
17      tx management frames
124     tx frames discarded prior to association
9148    tx failed 'cuz too many retries
95905   long on-chip tx retries
2       tx frames with no ack marked
837     tx frames with an alternate rate
19345   rx failed 'cuz of bad CRC
1       rx discarded 'cuz frame too large
1500378 packet recv on the interface
2       rx PHY errors:
    2 OFDM restart
512     periodic calibrations
30856   rate control checks
9       rate control raised xmit rate
5       rate control dropped xmit rate
rssi of last ack: 36
rssi of last rcv: 31
1       switched default/rx antenna
Antenna profile:
[1] tx  1341338 rx  1595910

-------end NRVU info---------

-- 
<=+=+=+==+=+=+==+=+=+=+=+=+=+=+=>
Edwin Whitelaw, P.E.
New River Valley Unwired, LLC
2200 Lonesome Dove Dr
Christiansburg, VA 24073
540-239-0318





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