[Cerowrt-devel] Cerowrt 3.3.8-10 is released

Dave Taht dave.taht at gmail.com
Thu Jul 12 20:43:13 EDT 2012

On Thu, Jul 12, 2012 at 2:51 PM, Dave Taht <dave.taht at gmail.com> wrote:
> I enabled crypto not via on the 2.4ghz interface on the -11 release
> and it worked.
> I DID have to do a clean reboot tho.
> 5.x is showing a new problem.

Sorry for the flurries of emails, I am literally 95% into a suitcase right now.

The 5ghz issue I was seeing is due to the ubuntu 3.5 kernel I was
using not doing 5ghz at all!

I did manage to connect at 5ghz via another box, and get a dhcp
address, and use crypto. It did take seemingly forever to get a crypto
connection, perhaps that is an entropy problem.

So, treat -10 and -11 with kid gloves and revert to 3.3.8-6 if you have to.

I did some more lab (rather than field tests) on 3.3.8-11, in
conditions where I should be getting 100+Mbit, and would get ~20Mbit
for a single stream download, and a sum of 66Mbit for 4 streams, so
utilization is poor. Originally, I was writing this off to losing
aggregation performance with the qlen_be change from 128 to 3. Now it
appears to be more subtle and fq_codel/wireless framing related.

Latency stayed low though, and that was my primary goal for this
release. Much works lies ahead to get serious bandwidth back into the
system while keeping low latency, however those that need 50Mbit+ and
actually have wireless nodes that can do that - can fiddle all they
like with qlen_be and/or various values for fq_codel's target in


On this string of tests I'd tripled the BE queue size from 400 to
1200, and at these speeds I would see the BE queue not get higher than
700, so this got me out of the persistently
dropping tail state and into a more codel-ing state:

http://www.bufferbloat.net/issues/401 seems to be better but I can
crash the beast at where
we are right now if I fully exercise 3 of the wireless queues (this
isn't going to happen to people
that aren't flooding the box on every queue, but it's easy to
duplicate as per the bug)

> On Thu, Jul 12, 2012 at 4:55 PM, Dave Taht <dave.taht at gmail.com> wrote:
>> Might have been the bug felix fixed in -11
>> Might also have corrupted the /etc/config/wireless and/or
>> /etc/config/network file too. if you ended up with a wlan0-1 in there
>> that would be it...
>> I too rarely use the gui interface.
>> On Thu, Jul 12, 2012 at 4:45 PM, Maciej Soltysiak <maciej at soltysiak.com> wrote:
>>> Hi,
>>> Just flashed WNDR3800 with 3.3.8-10 and I get a weird problem.
>>> After flashing it works fine, until I change radio0 and 1 wifi settings: set
>>> WPA2, set channel, etc.
>>> After save&apply, on a cilent PC I am able to see the networks on the list
>>> but it's not possible to connect.
>>> I believe the client associates with the AP, but it has an APIPA address.
>>> Happens to normal and guest interfaces too, even if I don't touch guest
>>> interfaces.
>>> I logged in over the wire to see if dhcpd was running and it was, but since
>>> I can't find logs in the usual place I will now fallback to different
>>> firmware.
>>> Could that be a known issue?
>>> Regards,
>>> Maciej
>>> On Wed, Jul 11, 2012 at 6:56 PM, Maciej Soltysiak <maciej at soltysiak.com>
>>> wrote:
>>>> Hi Dave,
>>>> Thanks for a good, lengthy update. I wish you pleasant time travelling.
>>>> One question on ECN though.
>>>> On Tue, Jul 10, 2012 at 3:43 AM, Dave Taht <dave.taht at gmail.com> wrote:
>>>>> - ECN dropping - after several high level conversations with many
>>>>> people smarter than me, I decided that dropping ECN packets at a
>>>>> certain point made sense. So did everyone else. The "certain point"
>>>>> remains puzzling to all, and
>>>>> rather than continue to waste time on it in cero I decided to play
>>>>> with models instead, and frankly, hope that someone else comes up with
>>>>> some sane way to combine ECN and codel sojourn time.
>>>> So if we're dropping ECN packets and not of trying to allow them through
>>>> to communicate congestion am I better of enabling ECN on clients on my
>>>> network or not?
>>>> Regards,
>>>> Maciej
>> --
>> Dave Täht
>> http://www.bufferbloat.net/projects/cerowrt/wiki - "3.3.8-6 is out
>> with fq_codel!"
> --
> Dave Täht
> http://www.bufferbloat.net/projects/cerowrt/wiki - "3.3.8-6 is out
> with fq_codel!"

Dave Täht
http://www.bufferbloat.net/projects/cerowrt/wiki - "3.3.8-6 is out
with fq_codel!"

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