Packet loss/errors/delays.

[Justin]

Hi,

I have been pulling my hair out with issues with HostAP, and I cannot seem to
get my head around it.  I'm hoping someone can point me in the right
direction.

Here's the situation:

I have a Linksys WRT320n running OpenWRT I am trying to take out of service in
favour of a mini-ITX box I've built.  The WRT320n works nicely, but its
throughput stinks.  My Internet connection is 75Mbps, but it can't handle >
~30.

With the WRT320n, a ping from my desktop to the router takes ~1ms pretty
consistently.. there's a little deviance occasionally, but never more than
10ms.

With HostAP, it jumps all over the place.  I experience 5-10% packet loss,
sometimes receive DUP packets, and the ping times range from 5-6ms all the way
up to 8-900ms.  I don't know what series of events I do that cause it, but
sometimes packet latency approaches 3000-4000ms, and loss up to 30%.

The card I'm using is an Atheros AR9285 mini pci-e adapter.  At first I
thought it might be the adapter's fault, so I bought a Broadcom BCM4321 and
suffered the exact same issues.

I am running Gentoo and have tried hostapd 0.7.3, hostapd 1.0-r1, and the
current git as of today.  All have the same outcome.

To try and narrow down the issue, I have cut my hostapd.conf file to contain
only:

ssid=testap
channel=1
interface=wlan0
driver=nl80211
auth_algs=1

I've tried changing channels, too (although that's the channel the wrt320n
operates on.)

Any device can see and connect to the AP just fine, but the latency and
connection stability is a mess.

What's equally puzzling is that throughput is stellar; I can transfer very
quickly.  Except when the packet loss inevitably goes up to 30% and latency
starts to get into multiple seconds.  And ssh connections never make it
through the night or go without long pauses/disconnects.

hostapd with -dd doesn't return anything particularly useful, but I haven't
been able to make sense of which logging commands and which log levels will
output anything useful.

If I use the ar9285 in that box as a wireless client with wpa_supplicant, it
works flawlessly; ping times that are sub-1ms, and 0% packet loss.

I'm hoping someone here can point me in the right direction for debugging
and/or making sense of this.

Ideas?

Justin