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Re: [LUG] Anyone on a blueyonder cable connection?

 

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Simon Waters wrote:
dd...> Mark Evans wrote:
>>> --- bbc.co.uk ping statistics ---
>>> 20 packets transmitted, 17 received, 15% packet loss, time 19166ms
>>> rtt min/avg/max/mdev = 80.415/1565.696/3886.348/1272.494 ms, pipe 4
>> --- bbc.co.uk ping statistics ---
>> 20 packets transmitted, 20 received, 0% packet loss, time 19043ms
>> rtt min/avg/max/mdev = 1841.429/2927.215/4401.177/711.007 ms, pipe 5
>>
>> Even without the packet loss the time taken is quite awful.
> 
> Guess uncontended business bandwidth from them is better.
> 
> --- bbc.co.uk ping statistics ---
> 20 packets transmitted, 20 received, 0% packet loss, time 19173ms
> rtt min/avg/max/mdev = 9.058/105.464/1144.053/253.871 ms, pipe 2
> 
> Our stats depend which server I use because we traffic shape, and some
> boxes are eating more than their allocated proportion of bandwidth. In
> which case I see worse stats pinging the local router, as it is the
> other side of the traffic shaper ;)

I came across something on virginmedia.support.broadband.cable which
suggested changing the MTU to 1492

Which gives the result of
- --- bbc.co.uk ping statistics ---
20 packets transmitted, 20 received, 0% packet loss, time 19078ms
rtt min/avg/max/mdev = 13.887/153.476/279.098/68.833 ms

It also results in slashdot.org appearing in a few seconds, whereas
previously it would take several minutes and even look like it was in
"text only" mode.

> Problems we see look more like when they introduced a content proxy into
> HTTP streams by mistake. When it works it is fine performance wise,
> otherwise the HTTP requests just hang.

By the looks of things one which can't cope with an MTU greater than
1492. (Which implies PPPoE being involved somewhere.) It appears to be
all traffic, not just HTTP(S). I was also seeing some strange behavior
with SSH connections, which changing the MTU has also fixed.

"ifconfig eth0 mtu 1492" appears to be a workaround...

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