[LEDE-DEV] [OpenWrt-Devel] latency on PPPoA ADSL Annex A on using Lantiq

[Rich Brown]

Hi Daniel,

(I feel like a one-trick pony here, but...) Could this be bufferbloat? Maybe not, but here's how to test:

Use the procedure for "A Quick Test for Bufferbloat" at https://www.bufferbloat.net/projects/cerowrt/wiki/Tests_for_Bufferbloat/#a-quick-test-for-bufferbloat Watch to see if the ping times increase during download/uploads then drop back down.

If the ping times do increase, consider installing luci-app-sqm as suggested on https://www.bufferbloat.net/projects/cerowrt/wiki/What_to_do_about_Bufferbloat/

Best regards,

Rich


> On Aug 4, 2016, at 3:10 PM, Daniel Niasoff <daniel at redactus.co.uk> wrote:
> 
> Hi Donald,
> 
> Thanks for responding
> 
> The MTU seems fine.
> 
> This is the WAN link
> 
> pppoa-wan Link encap:Point-to-Point Protocol
>          inet addr:2.25.173.155  P-t-P:172.16.11.136  Mask:255.255.255.255
>          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1492  Metric:1
>          RX packets:94409 errors:0 dropped:0 overruns:0 frame:0
>          TX packets:85742 errors:0 dropped:0 overruns:0 carrier:0
>          collisions:0 txqueuelen:3
>          RX bytes:75750172 (72.2 MiB)  TX bytes:14369708 (13.7 MiB)
> 
> I sent a 1492 byte icmp request externally which got through.
> 
> root at ubuntu:~# ping -s 1464 2.25.173.155
> PING 2.25.173.155 (2.25.173.155) 1464(1492) bytes of data.
> 1472 bytes from 2.25.173.155: icmp_seq=1 ttl=57 time=49.4 ms
> ^C
> --- 2.25.173.155 ping statistics ---
> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
> rtt min/avg/max/mdev = 49.439/49.439/49.439/0.000 ms
> 
> So MTU looks fine.
> 
> Thanks
> 
> Daniel
> 
> From: Donald Chisholm [mailto:donald.chisholm at gmail.com] 
> Sent: 04 August 2016 19:41
> To: Daniel Niasoff <daniel at redactus.co.uk>
> Subject: Re: [OpenWrt-Devel] latency on PPPoA ADSL Annex A on using Lantiq
> 
> Hi Daniel,
> 
> I just saw your message on the LEDE mailing list.  The freezing and catching up sounds like a MTU problem.  Could there be a MTU mismatch on the ADSL interface (1500 <->1492)?
> 
> Donald
> 
> On Thu, Aug 4, 2016 at 6:47 AM, Daniel Niasoff <mailto:daniel at redactus.co.uk> wrote:
> Hi,
> 
> I am quite desperate because I have a project going with these routers and I am running really late.
> 
> Can anyone spare some time to help me, I am willing to pay an hourly rate for the time if it will help.
> 
> This issue only occurs on ADSL. On VDSL performance is really good even using PPPoE.
> 
> The issue is a sluggish access to the CPU interface via ADSL, so for example if you are typing in a SSH client, it will keep freezing for a second or two, than catch up.
> 
> Routed traffic is fine.
> 
> Thanks
> 
> Daniel
> 
> -----Original Message-----
> From: Martin Blumenstingl [mailto:mailto:martin.blumenstingl at googlemail.com]
> Sent: 03 August 2016 08:03
> To: Alexander Couzens <mailto:lynxis at fe80.eu>
> Cc: Daniel Niasoff <mailto:daniel at redactus.co.uk>; mailto:openwrt-devel at lists.openwrt.org; mailto:lede-dev at lists.infradead.org; mailto:hauke at hauke-m.de; mailto:john at phrozen.org
> Subject: Re: [OpenWrt-Devel] latency on PPPoA ADSL Annex A on using Lantiq
> 
> On Tue, Aug 2, 2016 at 6:10 PM, Alexander Couzens <mailto:lynxis at fe80.eu> wrote:
>> On Tue, 2 Aug 2016 13:38:55 +0000
>> Daniel Niasoff <mailto:daniel at redactus.co.uk> wrote:
>> 
>>> I can provide remote ssh access if required. When using SSH you will
>>> notice it feels sluggish due to this issue.
>>> 
>>> Any ideas pleeeease, I am really stuck here?
>> 
>> I can confirm your problem with PPPoE on ADSL. Also noticed high
>> latency on ssh connection through the router.
>> I guess it's not in the DSL part, because when using the TD8970 as
>> modem with pass through everything is fine.
> someone else did performance/throughput testing on the HH5A, the results are posted here: [0]
> 
> I did not have time to look into this yet, but maybe Hauke or John have an idea what's going on.
> 
> 
> [0] http://openwrt.ebilan.co.uk/viewtopic.php?f=7&p=1189
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