[Cerowrt-devel] Status of SQM-Scripts integration into OpenWRT Barrier Breaker?

Toke Høiland-Jørgensen toke at toke.dk
Mon Aug 25 08:53:53 EDT 2014

"Frits Riep" <riep at riepnet.com> writes:

> I may be misunderstanding, but I thought this was a goal. Am I
> incorrect, or have the plans changed?

Don't think the plans have changed per se. More of a case of needing
more testing to be included in Openwrt.

There's some discussion of this here:


Testing is welcome!

> · I believe fq-codel is integrated into the latest available versions
> of Linux. If so, other than setting upload and download limits, do we
> already have buffer control handled with all newer OpenWRT releases?

Yes, fq_codel is included in the Linux kernel, and in Openwrt it is even
the default. So if your router is actually at the bottleneck
(physically), things should pretty much just work (in theory). However,
most routers are *not* at the bottleneck; there tends to be a modem of
some sort (whether cable, DSL or FIOS) in-between. Which is where
software rate-limiting (which is what SQM-scripts do) comes into play.

> · If so, do we still need to download and configure the packages,
> QOS-Scripts, and Luci-App-Qos? If so, do these packages do anything
> besides allow the configuration of Upload and Download limits?

Well, the QoS-script packages have some downsides and some upsides. The
main upside is configurability, I think. Including things like manually
classifying traffic etc. The downside is that it doesn't do IPv6 right,
and that SQM-scripts does link layer adaptation right, which I don't
think QoS-scripts do. Also, QoS-scripts is more complex and harder to
configure (I think).

> · If we can, in fact, control bufferbloat with OpenWRT and the latest
> Qos-scripts and Luci-App-QOS, then would the integration of SQM into
> OpenWRT provide much benefit in controlling bloat? If so, are there
> still plans to make that happen.

Well, I do believe there would be some merit to having SQM included (at
least as an optional package) in openwrt. More testing is the main thing
required, I think. And if we aim at completely replacing QoS-scripts,
(some of) the configurability needs to be added to SQM.

> I am very happy with the configuration of my home router running
> CeroWRT on a Netgear WNDR-3800 (running close to the latest build), on
> a Verizon FIOS connection at 75 Mbs Down / and 75 Mbs Up, and on
> running pings with Speedtest notice a definate difference in latency
> (very tight control) vs up to 100 ms latency.

Is this with SQM enabled? That usually tops out at around ~50Mbps due to
CPU limits...

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 472 bytes
Desc: not available
URL: <https://lists.bufferbloat.net/pipermail/cerowrt-devel/attachments/20140825/02978ad3/attachment.sig>

More information about the Cerowrt-devel mailing list