Hostapd+rt8x00 = packet drops.

Live forum: http://rt2x00.serialmonkey.com/viewtopic.php?t=6234

Lockywolf

22-07-2013 20:10:08

I have an ASUS card (PCI)

My lspci lloks the following way

[code27ox9a4h]03:02.0 Network controller: Ralink corp. RT2800 802.11n PCI
Subsystem: Ralink corp. Device 2860
Flags: bus master, slow devsel, latency 64, IRQ 17
Memory at fd9e0000 (32-bit, non-prefetchable) [size=64K]
Capabilities: [40] Power Management version 3
Kernel driver in use: rt2800pci
Kernel modules: rt2800pci
[/code27ox9a4h]

The card is used by a hostapd

[code27ox9a4h]mon.wlan0 IEEE 802.11bgn Mode:Monitor Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:off

wlan0 IEEE 802.11bgn Mode:Master Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:off

[/code27ox9a4h]

The problem is that I experience sudden (unpredictable) packet losts or ping increases

[code27ox9a4h]????? ?? 87.250.250.203: ????? ????=32 ?????=16?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=372?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=190?? TTL=55
???????? ???????? ???????? ??? ???????.
????? ?? 87.250.250.203: ????? ????=32 ?????=18?? TTL=55
???????? ???????? ???????? ??? ???????.
????? ?? 87.250.250.203: ????? ????=32 ?????=31?? TTL=55
???????? ???????? ???????? ??? ???????.
????? ?? 87.250.250.203: ????? ????=32 ?????=500?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=15?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=881?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=697?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=31?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=21?? TTL=55
???????? ???????? ???????? ??? ???????.
????? ?? 87.250.250.203: ????? ????=32 ?????=19?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=18?? TTL=55
???????? ???????? ???????? ??? ???????.
????? ?? 87.250.250.203: ????? ????=32 ?????=40?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=1294?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=430?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=729?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=22?? TTL=55
???????? ???????? ???????? ??? ???????.
????? ?? 87.250.250.203: ????? ????=32 ?????=143?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=62?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=18?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=119?? TTL=55
????? ?? 87.250.250.203: ????? ????=32 ?????=12?? TTL=55
[/code27ox9a4h]

You can see, that ping jumps from 17 to 116, and sometimes, ICMP packets are even lost.

If I ping from the router itself - ping varies from 8 to 17 with no drops, which seems okay.

Sometimes this behaviour may not appear for several days, but then it appears and starts annoying.
Sometimes, several reboots fix the problem, sometimes not. Sometimes, the problem disappears by itself for an extended period of time.

What can it be? How to fix the problem? It makes online games unplayable and Skype also suffers.

The same behaviour was observed since 2.6.X and currently is available on 3.9.4, x86_64.