[Bloat] SQM Settings for Bonded DSL?

[Sebastian Moeller]

Hi Jonathan,

> On Jun 21, 2018, at 15:16, Jonathan Foulkes <jf at jonathanfoulkes.com> wrote:
> 
> Hi Rich, Sebastian,
> 
> Most bonded modems do a good job of making the line look just like a single, higher-capacity line. The only major issues I’ve observed is when the bonded lines have some asymmetry to them (e.g. one link has weaker SNR), then the bond drops, re-synchs and continues. But occasionally, it will run for extended periods at 50% capacity (i.e. on only one of the lines).
> It uses PMT protocols, so not at all like mwan3, as any one connection can achieve full throughput of the bonded set.
> 
> I have data on hundreds of bonded lines, and other than the scenarios I mentioned above about bad bonds, as far as SQM goes, it behaves just like any other DSL line of equal capacity. So all the same guidelines would apply.
> 

Thank you very much, all very useful to know.


@Rich, could I ask you to try to run the https://github.com/moeller0/ATM_overhead_detector on your shiny bonded link? I am really curious how this will cope with such a link (I expect no issues, but the proof and the pudding thing still applies).

Also I see that bonding might have additional overhead that might not be per packet so will not be picked up by ATM_overhead_detector, so you might need to aim a bit lower with the shaper settings than usually.

Best Regards
	Sebastian




> I hope that helps,
> 
> Jonathan Foulkes
> 
>> On Jun 21, 2018, at 7:14 AM, Sebastian Moeller <moeller0 at gmx.de> wrote:
>> 
>> Hi Rich,
>> 
>> 
>> 
>>> On Jun 21, 2018, at 13:08, Rich Brown <richb.hanover at gmail.com> wrote:
>>> 
>>> Hi folks,
>>> 
>>> Our local DSL ISP (Consolidated Communications, Inc, formerly Fairpoint) recently installed a Smart/RG SR555ac (https://www.smartrg.com/sr555ac) bonded ADSL2 modem.
>>> 
>>> I seem to remember earlier messages stating that the dual queues in the DSL modem screwed up (or, de-optimized) the SQM in the router. 
>> 
>> 	As far as I can see this should not really cause an issue (besides that latency for single packets will be limited by the fact that you have two half-total-bandwidth links) except maybe that there might be additional overhead for the bonding on the link, but I have never looked at channel bonding so this is pure spekulation. I assume here that your Modem handles the bonding transparently. I could envision that running an non-transparent load-balancer (like with mwan3 under openwrt) might introduce issues for sqm, but if all you see is one ethernet link to the modem I do not expect any major quirks (except latency not being in line with the expectancy from total bandwidth).
>> 
>>> 
>>> The web GUI does provide info on SNR, sync rates, etc. Any advice for SQM beyond the standard, "measure the no-SQM speed, then start at 5% below..."? Thanks.
>> 
>> 	I am curius myself and would like to ask you to keep me/the list posted on whatever you find out about the applicability of sqm to bonding.
>> 
>> Best Regards
>> 	Sebastian
>> 
>> 
>>> 
>>> Rich
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