Bug #218

2.4 ghz dropping connections

Added by Dave Täht on Jul 31, 2011. Updated on Apr 21, 2012.
Closed Urgent Dave Täht

Description

Richard Smith from olpc writes in with his experience in China:

For most of us it worked fine but we actually didn’t use it much this time. Quanta provided us with a AP instead. Its was some fancy Motorola PoE job. The network was a wpa network which is a hassle for doing firmware upgrade and software imaging via http.

We switched to the wndr briefly so we had an open network. Sadly you just can’t run an open network at anymore. Loads of squatters appear. You can’t bandwidth restrict them since the XO’s are in the same catagory. It work ok except for one of the other developers who complained that his connection to 2.4Ghz keep dropping. Most of the rest of us were on 5G and didn’t see a problem. Due to that complaint we switched back to the Motorola and just dealt with the wpa network.

I took the router back with me to the hotel at night and used it without problems. I had to turn on encryption for 2.4G (again due to squatters) but I used the 5G open.

I think I have a possible solution for the open network for the next time. I think I can use nodogsplash with a site wide password so that once a MAC has been authorized it will stay that way. I’m not sure how I’ll deal with firmware access (no browser). I’ll have to craft up a recipe for doing a post with the right values so XO’s can auth from the firmware.

Not sure about the 2.4 dropping complaint but given that there will be many creowrt releases between now and then I’m not going to worry about it.

History

Updated by Dave Täht on Jul 31, 2011.
I have heard multiple reports of 2.4 ghz weirdnesses over the last 4 months with no solid data on what kind of hardware it was happening on. Could I convince some folk to install the lastest release candidate of cerowrt, get connected at 2.4 ghz (using both crypto, and not!), and stay online for a while - days, even - to see what happens? so we can gain insight into the existence or non-existence of this problem?

A temporary home for cerowrt release candidates is at:

http://huchra.bufferbloat.net/~cero1/

I hope to get an rc5 out late this coming week.

And I hope we get the testlab back up again soon.

Updated by Dave Täht on Jul 31, 2011.
Matt, Jacopo, could you ‘hang out’ on your routers at 2.4ghz and for a long time… and see if they drop the connect(s)? If not, let me know your hardware. If so, let me know your hardware.
Updated by David Taht on Sep 17, 2011.
———- Forwarded message ———-
From: Peter Naulls peter@chocky.org
Date: Fri, Sep 16, 2011 at 11:26 AM
Subject: [OpenWrt-Devel] Ath9k/hostapd connection dropping problems
To: OpenWrt Development List openwrt-devel@lists.openwrt.org

Some of this is speculation. I wish I had more precise details. This is
true
of all trunk versions in last few weeks, when I started using my G300H (v2)
as an AP. This includes upto version r28254, which includes yesterday’s
mac80211 patches, but not today’s spam fixes.

I have two Linux machines connecting to it. After some amount of time - or
what seems more likely, data, the WiFi connections will drop. If left
alone, they will come back after about 5 minutes. But it’s usually
faster to reboot the router.

I believe that:

  • LAN side is unaffected.
  • It happens after a certain about of traffic, rather than time, since it’ll
    be fine during the night when not much is happening, but be triggered during
    a download etc during the day.
  • Attempts to reproduce by running large amounts of traffic with iperf from
    WiFi -> Wired LAN have been inconsistent.
  • In one case where I saw it triggered, I restarted hostapd, and it seemed
    to
    come back, although NetworkManager on Ubuntu become confused, so I’m
    not certain.
  • There is nothing of consequence in kernel logs, apart from regular
    messages
    from hostapd about group key handshake.

So, I’m after ideas about more precise information I can gather, debug
I can turn on, etc, etc.

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Updated by David Taht on Sep 17, 2011.
———- Forwarded message ———-
From: Felix Fietkau nbd@openwrt.org
Date: Sat, Sep 17, 2011 at 12:28 AM
Subject: Re: [OpenWrt-Devel] Ath9k/hostapd connection dropping problems
To: OpenWrt Development List openwrt-devel@lists.openwrt.org

On 2011-09-17 8:50 AM, Felix Fietkau wrote:

On 2011-09-17 1:54 AM, Peter Naulls wrote:

> On 09/16/2011 12:53 PM, Jim Henderson wrote:
>
>> On Fri, 16 Sep 2011 15:08:15 -0400, Mark Deneen wrote:
>>
>>
>> In the end, I ended up reverting to build 27572, which I knew worked
>> prior to the upgrade.
>>
>
> I reverted the mac80211 package only to 27572 earlier today, and it seems
> to now
> be working correctly. Felix? ;-)
>
27572 is very old, please test 28092

Actually, please test 27957 instead.

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Updated by Dave Täht on Sep 17, 2011.
Updated by Dave Täht on Apr 21, 2012.
Lacking further data, I’m closing this bug.

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