Re: [Cerowrt-devel] cerowrt 3.3.8-17 is released

[Sebastian Moeller <moeller0@gmx.de>]

Hi William,


On Aug 15, 2012, at 3:57 PM, William Katsak wrote:

> I agree with this assessment as far as behavior goes.  With my recent experimentation on a Russian DSL line, I was seeing ~1200ms of uplink buffer reported (Netalyzr) natively, but as soon as I got the AQM running properly, that went away completely. 

	QOS or simple_qos.sh? I might switch to simple_qos next to see the effects there.

best
	Sebastian

> 
> Bill
> 
> Sent from my iPhone
> 
> On Aug 15, 2012, at 6:53 PM, "dpreed@reed.com" <dpreed@reed.com> wrote:
> 
>> Just to clarify, the way Netalyzr attempts to measure "uplink buffering" may not actually measure queue length.   It just spews UDP packets at the target, and measures sender-receiver packet delay at the maximum load it can generate.   So it's making certain assumptions about the location and FIFO nature of the "bottleneck queue" when it calculates that.
>>  
>> I don't think this is good news that you are reproting.
>>  
>> Assuming codel is measuring "sojourn time" and controlling it properly, you should not see 2.8 *seconds* of UDP queueing delay on the uplink - packets should be being dropped to keep that delay down to under 10 milliseconds.
>> I have no idea how that jibes with low ping times, unless you are getting the ICMP packets spoofed.
>>  
>>  
>> -----Original Message-----
>> From: "Sebastian Moeller" <moeller0@gmx.de>
>> Sent: Wednesday, August 15, 2012 1:23pm
>> To: "Dave Taht" <dave.taht@gmail.com>
>> Cc: cerowrt-devel@lists.bufferbloat.net
>> Subject: Re: [Cerowrt-devel] cerowrt 3.3.8-17 is released
>> 
>> Hi Dave,
>> 
>> great work, as always I upgraded my production router to the latest and greatest (since I only have one router…). And it works quite well for normal usage…
>> Netalyzr reports around 2800ms seconds of uplink buffering, yet saturating the uplink does not affect ping times to a remote target noticeably, basically the same as for all codellized ceo versions I tested so far...
>> 
>> Some notes and a question:
>> I noticed that even given plenty of swap space (1GB on a usb stick), using http://broadband.mpi-sws.org/residential/ to exercise UDP stress (on the uplink I assume) I can easily produce (I run the test from a macosx via 5GHz wireless over 1.5 yards):
>> Aug 15 01:16:29 nacktmulle kern.err kernel: [175395.132812] ath: skbuff alloc of size 1926 failed
>> (and plenty of those…). 
>> What then happens is that the OOM killer will aim for bind (reasonable since it is the largest single process) and kill it. When I try to restart bind by:
>> root@nacktmulle:~# /etc/rc.d/S47namedprep start
>> root@nacktmulle:~# /etc/rc.d/S48named restart
>> Stopping isc-bind
>> /etc/chroot/named//var/run/named/named.pid not found, trying brute force 
>> killall: named: no process killed
>> Kicking isc-bind in xinetd
>> rndc: connect failed: 127.0.0.1#953: connection refused
>> And bind does not start again and the router becomes less than useful. Now I assume I am doing something wrong, but what, if you have any idea how to solve this short of a reboot of the router (my current method) I would be happy to learn
>> 
>> 
>> 
>> best regards
>> sebastian
>> 
>> On Aug 12, 2012, at 11:08 PM, Dave Taht wrote:
>> 
>> > I'm too tired to write up a full set of release notes, but I've been
>> > testing it all day,
>> > and it looks better than -10 and certainly better than -11, but I won't know
>> > until some more folk sit down and test it, so here it is.
>> > 
>> > http://huchra.bufferbloat.net/~cero1/3.3/3.3.8-17/
>> > 
>> > fresh merge with openwrt, fix to a bind CVE, fixes for 6in4 and quagga
>> > routing problems,
>> > and a few tweaks to fq_codel setup that might make voip better.
>> > 
>> > Go forth and break things!
>> > 
>> > In other news:
>> > 
>> > Van Jacobson gave a great talk about bufferbloat, BQL, codel, and fq_codel
>> > at last week's ietf meeting. Well worth watching. At the end he outlines
>> > the deployment problems in particular.
>> > 
>> > http://recordings.conf.meetecho.com/Recordings/watch.jsp?recording=IETF84_TSVAREA&chapter=part_3
>> > 
>> > Far more interesting than this email!
>> > 
>> > 
>> > -- 
>> > Dave Täht
>> > http://www.bufferbloat.net/projects/cerowrt/wiki - "3.3.8-17 is out
>> > with fq_codel!"
>> > _______________________________________________
>> > Cerowrt-devel mailing list
>> > Cerowrt-devel@lists.bufferbloat.net
>> > https://lists.bufferbloat.net/listinfo/cerowrt-devel
>> 
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