low latency settings for wireless backhaul

[someuser08]

I have a couple of XT8s in AP mode connected with wireless backhaul. I spent quite a bit of effort before on optimizing wireless connection for speed/bandwidth and is able to have ~350Mbps internet speed through the child node (out of Gigabit on the main node) which I'm happy with, however it turns out that at those speeds you can still have a feeling of slowness due to latency of wireless connection (that you can feel sometime in video conferencing and media heavy social media apps). So I'm trying to go into other direction now - I do not care about speed (even if it drops 50-100Mbps its still a lot to have anyway), but want to optimize the latency performance of the backhaul 5-2 first (and then then 5-1 for laptop and mobile usage).

So for the 5-2 I have disabled pretty much all the options and ended up with this. Anything else to tune for latency specifically?

 

[someuser08]

Just to follow up. I ended up re-arranging node placement to archive slightly better connectivity: backhaul is now connected at ~800mbps with real life internet speed of ~450mbps both ways). To my dismay Zoom calls are still choppy from time to time. I can't believe that at those speeds and latency < 100ms I'm having such a problem. Could it be Zoom specific issue on ISP side? What can do more?

P.S. One last attempt - I've set SQM running at 250Mbps on the gateway and now I get A+ bufferfloat rating (20ms latency with zero increase during upload/download), so if this doesn't work I'm out of ideas...

 

[degrub]

do you get the same zoom issues if you hardwire into the primary router ?

 

[someuser08]

I can't easily test this, but I'm 99% certain it will be OK. Even when i do manual testing of calls with friends (who are on good connection as well) it's not reproducible, but long calls (over far longer geo distance) my kid does for tutoring are affected (could be 30-40 min in the problems would be starting). It's almost as if the quality of the call equals of sum of latency of all the participants. So zoom says it should be less than 150ms, but I wonder if the other participant is over 100ms then it leaves me with less that 50ms (I'm really not sure Zoom how zoom handles high latency of just one participant).