Thinkbroadband sawtooth effect 17.01.1

Good morning,

My family all run TPLINK 1043ND V2's as our main router. They all had OpenWRT Chaos Calmer 15.05.1 running on them flawlessly. A few days ago I decided to switch them all to LEDE 17.01.1 which went without issue.

However, we have thinkbroadband broadband qaulity monitor setup to all three connections ( and whilst it is no major issue, and the router appears to be performing just the same as previously. I have noticed a sawtooth affect appear with latancy on each connection after the upgrade.

I am linking to a few graph snapshots on pastebin so you can see this (cannot paste the direct images as I am a new user and can only share 2 URLS). 2 from the 20th April which is the day I upgraded all the routers - you can see the point the upgrade ocurs as the sawtooth effect begins straight away and you can see that this does not happen until then on each connection followed by two graphs on the 23rd April (selected this day randomly).

Does anyone have any idea why this is ocurring on LEDE 17.01.1?


Which QoS package you are using? SQM?

That doesn't look like anything really typical for LEDE or Openwrt. Looks like something every 40-45 minutes triggers latency to a slightly higher level and then it comes down.

One thing that could be imagined, is some QoS tool either used by you or your ISP that resets its measurements every 45 minutes and then the latency worsen somewhat and then it starts improving when QoS gets more touch to the line conditions.

Only one of the two routers that I've shared the graphs for has SQM configured (Edgehill).

When i was running OpenWRT none of the routers had SQM at all.

I think any ISP QoS needs ruling out as it didn't ocurr beforehand - two of the connections are on the same ISP and the other is on BT and all three have done this since.

No ideas anyone?

Sorry to dig up such an old post, but I've just switched to the latest OpenWRT build and I am pleased to say that the sawtooth effect is finally gone and is like it was pre LEDE when I was running the OpenWRT builds.

Here is a snapshot graph which shows this clearly going away once the router was upgraded: