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Today's Topics:
1. Re: Are Virginmedia (VM) Telling me Porkies? (Pete Carpenter)
2. Re: Sysctl.d - stopping "stop job" delaying shutdown
(Alex Butcher)
3. Re: Are Virginmedia (VM) Telling me Porkies? (Alex Butcher)
4. Re: Are Virginmedia (VM) Telling me Porkies? (Amias Channer)
5. Re: Are Virginmedia (VM) Telling me Porkies? (Alex Butcher)
----------------------------------------------------------------------
Message: 1
Date: Wed, 1 Jun 2016 15:35:45 +0100
From: Pete Carpenter <thehalovex@googlemail.com>
To: mark chard <machard.1984@gmail.com>, Bristol and Bath Linux User
Group <bristol@mailman.lug.org.uk>
Cc: Peter Hemmings <peternsomerset@virginmedia.com>, David Smith
<David.Smith@imgtec.com>
Subject: Re: [bristol] Are Virginmedia (VM) Telling me Porkies?
Message-ID:
<CAOCkmAvt_89+h5QNJvuByHg+q5Ze0dN37fTmVH5N94evWQ+1OA@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Hiya,
Having worked for 2 ISPs, one here and one in Australia, using a wide range
of hardware; that's short hand for 'God knows what the issue is, I hope a
powercycle will fix it'.
Won't help I'm afraid but I hope it lends some clarity!
Pete
On 1 June 2016 at 14:26, mark chard via Bristol <bristol@mailman.lug.org.uk>
wrote:
> They are telling you porkies buddy, even before the unifi AP I had no
> connection issues. Not unless they were caused by line drops.
> I would ask them for a replacement device and ask them to send that one
> for diagnostics.
> On 1 Jun 2016 2:23 pm, "David Smith via Bristol" <
> bristol@mailman.lug.org.uk> wrote:
>
>> > -----Original Message-----
>> > From: Bristol [mailto:bristol-bounces@mailman.lug.org.uk] On Behalf Of
>> > Peter Hemmings via Bristol
>> > After a further quite long discussion trying to get him to explain what
>> caused
>> > it he said it was a cable modem and they all have this problem if left
>> on 24/7
>> > and that I should switch it off every week to keep it at peak
>> performance!
>> >
>> > Is his explanation anyway near true, or am I being told "porkies"!?
>>
>> If it's true, then the design of their router is somewhat sub-optimal...
>> _______________________________________________
>> Bristol mailing list
>> Bristol@mailman.lug.org.uk
>> https://mailman.lug.org.uk/mailman/listinfo/bristol
>
>
> _______________________________________________
> Bristol mailing list
> Bristol@mailman.lug.org.uk
> https://mailman.lug.org.uk/mailman/listinfo/bristol
>
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Message: 2
Date: Wed, 1 Jun 2016 16:39:59 +0100 (BST)
From: Alex Butcher <lug@assursys.co.uk>
To: Peter Hemmings <peternsomerset@virginmedia.com>, Bristol and Bath
Linux User Group <bristol@mailman.lug.org.uk>
Subject: Re: [bristol] Sysctl.d - stopping "stop job" delaying
shutdown
Message-ID:
<alpine.LRH.2.11.1606011635240.31088@zlgugi.of5.nffheflf.cev>
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
On Wed, 1 Jun 2016, Peter Hemmings via Bristol wrote:
> "Potomac commented on 30 Mar":
>
> Create a file "/etc/sysctl.d/50-coredump.conf" with
> kernel.core_pattern=core
>
>
> What does this do
>From <http://man7.org/linux/man-pages/man5/core.5.html>:
"Naming of core dump files
By default, a core dump file is named core, but the
/proc/sys/kernel/core_pattern file (since Linux 2.6 and 2.4.21) can
be set to define a template that is used to name core dump files."
(Found by googling kernel.core_pattern)
> and is this just a bodge!?
<https://github.com/systemd/systemd/issues/2691#issuecomment-187593173>
seems to offer some explanation.
It does sound like a bodge to me, since it's just setting the core_pattern
to the default. Unless systemd is changing it - perhaps to generate multiple
core dump files, in which case setting it to 'core' will result in them
over-writing each other, which I /suppose/ could speed things up...
> (it does seem to stop the delay!)
> Regards
Best Regards,
Alex
------------------------------
Message: 3
Date: Wed, 1 Jun 2016 16:46:49 +0100 (BST)
From: Alex Butcher <lug@assursys.co.uk>
To: Peter Hemmings <peternsomerset@virginmedia.com>, Bristol and Bath
Linux User Group <bristol@mailman.lug.org.uk>
Subject: Re: [bristol] Are Virginmedia (VM) Telling me Porkies?
Message-ID:
<alpine.LRH.2.11.1606011641070.31088@zlgugi.of5.nffheflf.cev>
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
On Wed, 1 Jun 2016, Peter Hemmings via Bristol wrote:
> After being advised years ago to leave my router switched on 24/7, I had
> been doing this for years (with Eclipse).
[snip]
> After a further quite long discussion trying to get him to explain what
> caused it he said it was a cable modem and they all have this problem if left
> on 24/7 and that I should switch it off every week to keep it at peak
> performance!
You /should/ be able to leave network kit on 24/7/52/n.
However, consumer kit being what it is (i.e. built by the lowest bidder),
hardware and software quality can be... undependable. Consequently, much
consumer kit doesn't handle abnormal disconnections well, doesn't
renegotiate correctly every time, has firmware with memory leaks and so on.
And so periodic reboots/powercycles are a dumb way to limit the impact of
these problems.
If it's any consolation, my ADSL 2+ router has had problems maintaining an
optimal connection since I upgraded to full rate ADSL 2+. Consequently,
after forced disconnections (e.g. due to noise on my line, or a power
event), the connection often comes back with my upstream being ~40% of the
typical bitrate. Or, it doesn't come back at all... as happened when I was
on holiday recently! Oh well, one less unnecessary distraction from the
holiday itself!
Best Regards,
Alex
------------------------------
Message: 4
Date: Wed, 01 Jun 2016 09:13:19 -0700 (PDT)
From: Amias Channer <me@amias.net>
To: Alex Butcher <lug@assursys.co.uk>, Bristol and Bath Linux User
Group <bristol@mailman.lug.org.uk>
Cc: Peter Hemmings <peternsomerset@virginmedia.com>
Subject: Re: [bristol] Are Virginmedia (VM) Telling me Porkies?
Message-ID: <1gdtgnvfwisrntxcwfdmizmfi-0@mailer.nylas.com>
Content-Type: text/plain; charset="us-ascii"
Hello Luggers,
Resetting is only really a problem with ADSL type connections and not DOCSIS
connections like virgin.
Because ADSL is trying to get the most out of an old line it has to do a lot
of complex compression and line driving tricks, these require a bit of line
analysis to make them truely effective. When you reset your ADSL connection
there will be a certain amount of renegotionation of the speed as this
analysis might have yeilded a different result. Logs are also kept of restarts
and a line that restarts too often will often have the speed lowered to try
and make it more stable. When a line has been running stably for a while both
ends will attempt to push the speed up , on reconnection you will typically
loose those boosts when it comes back. If you restart your DSL every night the
isp will think you have a problem.
With Virgin none of this applies because there network is not having to do so
much work on compression and line stability , it typically sets a stable speed
in a few seconds.
I care about wasting resources but really a wifi router that is sitting idle
is not a massive worry, especially if you have a green energy provider
providing your energy.
Cheers
Amias
On Jun 1 2016, at 4:47 pm, Alex Butcher via Bristol
<bristol@mailman.lug.org.uk> wrote:
> On Wed, 1 Jun 2016, Peter Hemmings via Bristol wrote:
>
> > After being advised years ago to leave my router switched on 24/7, I
had
> been doing this for years (with Eclipse).
>
> [snip]
>
> > After a further quite long discussion trying to get him to explain what
> caused it he said it was a cable modem and they all have this problem if
left
> on 24/7 and that I should switch it off every week to keep it at peak
> performance!
>
> You /should/ be able to leave network kit on 24/7/52/n.
>
> However, consumer kit being what it is (i.e. built by the lowest bidder),
hardware and software quality can be... undependable. Consequently, much
consumer kit doesn't handle abnormal disconnections well, doesn't
renegotiate correctly every time, has firmware with memory leaks and so on.
And so periodic reboots/powercycles are a dumb way to limit the impact of
these problems.
>
> If it's any consolation, my ADSL 2+ router has had problems maintaining an
optimal connection since I upgraded to full rate ADSL 2+. Consequently,
after forced disconnections (e.g. due to noise on my line, or a power
event), the connection often comes back with my upstream being ~40% of the
typical bitrate. Or, it doesn't come back at all... as happened when I was
on holiday recently! Oh well, one less unnecessary distraction from the
holiday itself!
>
> Best Regards,
Alex
>
> _______________________________________________
Bristol mailing list
Bristol@mailman.lug.org.uk
https://mailman.lug.org.uk/mailman/listinfo/bristol
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------------------------------
Message: 5
Date: Thu, 2 Jun 2016 10:31:46 +0100 (BST)
From: Alex Butcher <lug@assursys.co.uk>
To: Amias Channer <me@amias.net>, Bristol and Bath Linux User Group
<bristol@mailman.lug.org.uk>
Cc: Peter Hemmings <peternsomerset@virginmedia.com>
Subject: Re: [bristol] Are Virginmedia (VM) Telling me Porkies?
Message-ID:
<alpine.LRH.2.11.1606021025240.22256@zlgugi.of5.nffheflf.cev>
Content-Type: TEXT/PLAIN; charset=UTF-8; format=flowed
On Wed, 1 Jun 2016, Amias Channer via Bristol wrote:
> Resetting is only really a problem with ADSL type connections and not DOCSIS
> connections like virgin.
>
> Because ADSL is trying to get the most out of an old line it has to do a lot
> of complex compression and line driving tricks, these require a bit of line
> analysis to make them truely effective. When you reset your ADSL connection
> there will be a certain amount of renegotionation of the speed as this
> analysis might have yeilded a different result. Logs are also kept of
> restarts and a line that restarts too often will often have the speed
> lowered to try and make it more stable.
Agreed.
> When a line has been running stably
> for a while both ends will attempt to push the speed up , on reconnection
> you will typically loose those boosts when it comes back.
Replace 'will attempt' with 'should attempt' and 'will typically' with
'may', in my experience!
As an /entirely/ unrelated question... has anyone got any recommendations
for decent ADSL2+ routers? I don't care if it has WiFi (I do that on a DMZ
hanging off my firewall), but I do want optimal connections and solid
renegotiations in the event of line drops. Syslog and SNMP support are a
bonus.
> If you restart your DSL every night the isp will think you have a problem.
Agreed. In fact, when my upstream is a bit crappy, I try to leave it for a
while before giving a reboot to get it back to normal for exactly this
reason.
> With Virgin none of this applies because there network is not having to do
> so much work on compression and line stability , it typically sets a stable
> speed in a few seconds.
>
> I care about wasting resources but really a wifi router that is sitting idle
> is not a massive worry, especially if you have a green energy provider
> providing your energy.
If you have a fridge and/or freezer (even an A+ or better rated model), a
broadband router (probably 12W or less) is the least of one's worries. And,
like a fridge, a significant part of the value comes from being always-on
and virtually maintenance-free.
> Cheers
> Amias
Best Regards,
Alex
------------------------------
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