[Cerowrt-devel] SQM and PPPoE, more questions than answers...

[Sebastian Moeller]

Hi Edwin,


On Oct 15, 2014, at 14:02 , Török Edwin <edwin+ml-cerowrt at etorok.net> wrote:

> On 10/15/2014 03:03 AM, Sebastian Moeller wrote:
>> 	I guess it is back to the drawing board to figure out how to speed up the classification… and then revisit the PPPoE question again…
> 
> FWIW I had to add this to /etc/config/network (done via luci actually):
> option keepalive '500 30'
> 
> Otherwise it uses these default values from /etc/ppp/options, and then I hit: https://dev.openwrt.org/ticket/7793:
> lcp-echo-failure 5
> lcp-echo-interval 1
> 
> The symptomps are that if I start a large download after half a minute or so pppd complains that it didn't receive reply to 5 LCP echo packets and disconnects/reconnects.

	I have not yet seen these in the logs, but I will keep my eyes open.

> Sounds like the LCP echo/reply packets should get prioritized, but I don't know if it is my router that is dropping them or my ISP.

	I think that is something we should be able to teach SQM (as long as the shaper is running on the lower ethernet interface and not the pppoe interface). 

> 
> When you tested PPPoE did you notice pppd dropping the connection and restarting, cause that would affect the timings for sure…

	Nope, what I see is simply more variance in bandwidth and latency numbers and a less step slope on a right shifted ICMP CDF… I assume that the disconnect reconnects should show up as periods without any data transfer…. 

Mmmh, I will try to put the PPP service packets into the highest priority class and see whether that changes things, as well as testing your PPP options.

Thanks for your help

	Sebastian

> 
> Best regards,
> --Edwin
> 
> 
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