Apple devices and poor performance of Belkin RT3200

Installing and Using OpenWrt Network and Wireless Configuration
1

Hi All, I recently installed OpenWrt on a new Belkin RT3200 and have noticed the performance on apple devices is poor.

When in the browser is takes 3-5 seconds before the website starts to even load. Once the website is loaded performance is slightly better when on the same site but then if I switch website, again, takes 3-5+ seconds before it starts loading.

I tried several apple devices (macbook, ipad, iphone) and all the same. With the macbook, the performance is the same when cabled, so I don't think its a wifi issue.

I also tried on a windows laptop and android device and performance seems much better. The issue seems to be limited to apple devices.

I installed Openwrt using https://github.com/dangowrt/linksys-e8450-openwrt-installer
Upgraded firmware using Attended Sysupgrade
Enabled wifi, and set the post install tips https://openwrt.org/toh/linksys/e8450

  • Firmware Version: OpenWrt 22.03.2 r19803-9a599fee93 / LuCI openwrt-22.03 branch git-22.361.69894-438c598
  • Kernel Version: 5.10.146

Based on other posts I've seen, I also tweaked the wireless settings to "better support" apple devices

  • For device: option cell_density '3'
  • For iface: option dtim_period '3'
    but haven't seen big differences and as mentioned the issue is not only with wireless.

Has anyone else experienced this or know what the issue could be? Thanks

2

There are several threads about this issue, try a search.

2 Likes
3

I've gone through several posts but have not found anything that has helped. What should I be searching for?

4

To me this sounds like it could be related to OpenWrt announcing a ULA IPv6-prefix in case of your ISP not providing IPv6 connectivity (do they?). If so, you could try to switch off DHCPv6 and RA on your LAN interface.

5

Hi Daniel, I tried that but didn't seem to make a difference. I believe my ISP does provide IPv6 connectivity.
I did tests on fast.com and in both cases the loaded latency is over 500ms on my macbook
Loaded latency on android device is ~20-30ms

6

Just to confirm 100% that I understood correctly: You are also seeing this problem when connecting the device via Ethernet while WiFi is switched off, hence making sure that traffic takes the wired path.

Do you have any additional software installed (e.g. DNS filters like adblock) on the RT3200?

7

Correct, I am seeing the problem when connected via Ethernet with wifi disabled.

I have installed adblock and wireguard now, but the issue existed (and still exists) before I installed them.

When doing the tests I reset the router and only did the post install tips

8

If anyone else stumbles here, irqbalance has improved the situation. Still not reaching the speed I should be reaching, but the ping and latency have drastically improved.

9

Are you sure? When I had that running some of my devices (RT3200, RPi4), it didn't seem to do anything that the kernel wasn't already doing. You can check here:

cat /proc/interrupts

Some of those are bound to a particular CPU and cannot be changed, but if you see an even distribution of others, that is what I believe you're looking to see.

My point is that with 5-6 h of uptime without it, the output is similar to 5-6 h of uptime with it running.

Try disabling it, reboot, and see for yourself.