High Latency Web Speeds RT-AC87U

[Nathan Johnston]

I am experiencing a regular issue where web browsing becomes slow and certain web tests report high latency. A reboot always fixes the problem, but it reoccurs again within 24 hours.

My router is an AC-RT87U running Merlin 380.58. This problem also occurs on stock firmware with a similar frequency.

Detailed symptoms:

• Slow browsing on all browsers, wired, 2.5 Ghz and 5.8 Ghz wireless. This appears to be latency in establishing connections, as page elements appear to load quickly, once they load (ie. no window shade effect on large images)
• DSL reports speed test, refuses to run the bufferbloat analysis because of a reported latency of ~800ms, however actual reported speeds are as expected (~100mb/7mb)
• speedtest.net loads very slowly and the site selection process takes much longer than usual (5x longer maybe). Once the test runs, it reports speeds as expected (~100MB/7mb)
• A standard ping command reports expected latencies

I have tried a shotgun approach to changing settings (ie. QOS on/off, NAT acceleration on/off, etc.) but so far the only thing that actually works is a daily reboot.

I have adaptive QOS enabled and BW set as above, PPTP vpn is enabled, but is not used very much if at all, and I have a few clients with web filters and time restrictions.

Does anyone have a suggestion for an approach to troubleshoot this, or What features/configuration might be at issue?

 

[Nullity]

DNS problems perhaps?

 

[Nathan Johnston]

I thought of that, but when I configure a computer to use static DNS settings and bypass the router's internal DNS, the problem remains. I also have run a few DNS benchmarks during and after the issue, and the router DNS comes back as fast and reliable. I am wondering if it related to HTTP/S processing, as pure network tests (ie command line ping, tracert, DNS, etc) seem to work OK, but browser based stuff is what seems to show the issue most consistently. I could disable web filtering and see if that keeps the problem from reappearing. (I rebooted already today so everything is good at the moment)

I would like to use those filtering features however, so that's not an ideal solution.

--Edit---

I turned off everything in the AiProtection section except time limits. I will have to wait to see how things look in a day or two.

 

[sfx2000]

How are you connected upstream?

Cable, DSL, Fiber, Satellite, 3G/4G/LTE?

 

[Nathan Johnston]

How are you connected upstream?

Cable, DSL, Fiber, Satellite, 3G/4G/LTE?

Charter Spectrum Business 100MB Cable.

 

[sfx2000]

And also - does this happen just on 5GHz? or does this happen on both 2.4GHz and 5GHz...

the 87U is different than most...

 

[Nathan Johnston]

And also - does this happen just on 5GHz? or does this happen on both 2.4GHz and 5GHz...

the 87U is different than most...

Everything. 2.4 Ghz, 5Ghz, and Wired.

 

[sfx2000]

Everything. 2.4 Ghz, 5Ghz, and Wired.

Helps folks trying to analyze the problem, esp. with the 87U, where 5G-WLAN and LAN1 are managed by the Quantenna chip, and LAN2-4 and WLAN-2G are Broadcom, along with all routing...

If you roll back to pre-380 firmware, does the problem continue? the 380 builds have been, for a lack of a better word, interesting...

 

[Nathan Johnston]

That is an interesting configuration.

I might try a few more combinations to confirm that the issue is actually chipset independent given the extra complexity. I haven't tested on 2.4 Ghz as extensively, nor have I tried a different set of LAN ports. (Not even sure which particular LAN port the wired connection was in)

If (when) it happens again, I will consider rolling back to an earlier build. Any recommendations?

 

[sfx2000]

If (when) it happens again, I will consider rolling back to an earlier build. Any recommendations?

I would continue to test and see if this is specific to the Quantenna side, or a more general issue...

As for potential SW - might consider the @RMerlin releases, as he's done a fair amount of bug-mashing and general improvements...

 

[Nathan Johnston]

After almost a week, the problem has not occurred again and I have not rebooted.

It seems to me that the issue is related to AiProtection web filtering in some way, as I have changed nothing else.

 

[Nathan Johnston]

At some point I will re-enable some of the AiProtection features to see if I can narrow it down to a specific setting.