[Cerowrt-devel] very much a development build cerowrt-3.8.13-3 released

Dave Taht dave.taht at gmail.com
Sat May 18 17:13:55 EDT 2013

and at:


I want to clearly note that I can crash the router over wifi using the rrul
test easily. I can (furthermore) crash the x86 linux-3.9.2 iwl driver on my
laptop even more easier than I can crash the router. The combination of the
two problems are making debugging impossible.

So... pretty please... with sugar on top... don't install this on your
default gw?

If on the other hand, you have a jtag debugger handy, and don't have a iwl
card on your laptop, and can look into the wifi issues, please do so...
(all you have to do is bump up /etc/xinetd.d/netserver to 16 and run the
netperf-wrapper against it for a few minutes)

There are otherwise a huge number of interesting things that have
accumulated for this release cycle.

I was very happy that most of what was in Modena has landed in openwrt and
the mainline linux kernels last month. Relieved, actually. I felt that I
could take a break... even thought I could quit... spent a few days on a
beach in Morocco and got bored to death... so....

The BIG new thing in this release is a version CISCO's PIE AQM algorithm,
which after nearly a year of development and analysis was released as open
source last week. The version of pie I just put in cero has not been fully
verified to be correct, but has the additional features of ECN and TSQ
support over the original. I hope to bake this a lot more over the coming
week. (the wifi issue is annoying but secondary at the moment to finally!
finally! fiddling with PIE)

There was the usual huge resync with openwrt. dslite landed recently in
particular, but there have just been a huge number of updates across the
board that I've lost track of. FW3 for example, is a fast, in-c replacement
for the old firewall scripts, and openwrt is now using multi-table support
in preparation for handling src/dst routing better.

Toke contributed tahoe-lafs and suggested trying out the tinc vpn system,
so those are available as an optional package. tinc is kind of neat. a
meshy vpn system. Never heard of it before now.

Toke also has been a great help elsewhere, notably in getting a gui and
scripts going for the backend AQM system, working on a new build script to
make it easier for others to build cero, and lots, lots more.
Rich Brown & Toke updated the onboard documentation significantly
Electra convinced me to make batman-adv available (but not enabled) by
Babeld 1.4 has a new convergence smoothing algorithm (but quagga-babeld is
still the default)
OpenWrt's QOS web page and backend scripts have been replaced by the new
AQM page
The AQM scripts are now correct for EF and ECN.
fq_codel is now the default on everything with a quantum of 300

I have a very long list of things I'd like to see land in a stable version
of this before ietf Berlin (late july) - notably a ton of good stuff
happened in the linux-3.9 and current net-next series on the TCP front.
sctp support, maybe even mptcp support is looking semi-feasible.

only a package definition away from npt-66 support at this point, no
userspace dependencies left... anyone?

want better dlna and upnp support, too. Have no idea what's needed to fix

And there's GREAT things happening in dnsmasq that I doubt will land
anytime soon, but here's hoping. I ended up talking about dnsmasq a lot at
last week's talk at ripe.

(this talk was the first time anyone had ever asked me to talk about the
good stuff happening from the cerowrt development/user/open source model
and process, rather than about bufferbloat. It was kind of neat. But then I
only had 20 minutes and ended flat... It was my last talk of the "fq_codel
world tour". I return to the USA next week and plan to spend quite a while
in california.

if you are not as tired of me as I am, all the talks are linked to off of:



As a result of the tour... and having a chance to play a little guitar here
and there...

I am thinking of getting some t-shirts designed. Actually, as I figure most
people here already have a closet full of industry t-shirts, perhaps some
socks is more appro - symbolically for the fleet of foot! or (practically)
for those that have lost half their existing socks somewhere in europe...
Anyone have some good ideas as to a logo/design/sayings to put on socks?
Please start riffing...

the only idea I have t-shirt-tour-wise is this:


"We Beat the Bloat" - available in size XL, maybe?

anyway getting back to cerowrt plans...

I would like to fold in the "best of" the homenet and hipnet work...

I also plan to incorporate the now famous ietf demo as a package you can
run to demonstrate the effects of bufferbloat.

As always suggestions wanted, and patches gladly accepted.

Given the severity of the crash bug right now I don't know when this will
become a stable release series, but as it had been a while since putting
out a new one, nor had I communicated the feature creep, well, here you

Dave Täht

Fixing bufferbloat with cerowrt:

Dave Täht

Fixing bufferbloat with cerowrt:
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