Have to disconnect and reconnect to restore wifi speeds

Installing and Using OpenWrt
1

Hi all,

I have around 20 devices connected to openwrt Access point. Randomly, internet on the one of the device become extremely slow. Disconnecting and reconnecting restores speeds.

openwrt info

version: 18.06
channel: 36
channel width: 80Mhz
band: 802.11ac
AP is 3x3:3 MIMO
5Ghz radio: QCA9880
driver: ath10k_pci
version: 4.9.111
firmware-version: 10.2.4-1.0-00033

Running four SSIDs with VLAN: private, private-2g, devices and guests

Wireless Info on Macbook Pro

Macbook Pro 2015
3x3:3 MIMO
Tx rate: between 975 and1053 Mbps
mcs index: between 7 and 9
RSSI: -56 dBm
Channel: 36 (5GHz, 80MHz)

Tests

iperf

iperf3 server: 1Gb wired linux box
iperf3 client: Macbook Pro 2015, high sierra.

Before reconnect: around 12-20 Mbps
After reconnect: around 320-340 Mbps

fast.com

Before reconnect: around 140 Kbps - 1Mpbs
After reconnect: around 110-130 Mbps

Observations

  • When problem occurs, the client is at different distances from the Access Point. But it's never at a range where the RSSI is below -60 dBm.
  • Wifi readings on the laptop show excellent connection but the speeds are extremely slow.
  • Another laptop placed literally right next to the problematic laptop has normal speeds.
  • I checked it was DNS issue and changed the DNS servers.
  • I also moved the location of the AP.
  • logs don't show anything in particular

Connection is not dropped, it's just become really slow. It's not one particular client but random client at random times.

Any insight?

Thanks!

2

I suspect that it is a bandwidth starvation issue, that is some other client is utilizing the available bandwidth, since you have quite a lot of SSIDs and clients.
Have you verified what is the traffic during the time that the issue happens?

1 Like
3

@trendy

stats:

  • connection from ISP is 190 Mbps down and 30 Mbps up.
  • Max bandwidth used at peak hours is 70 Mbps down and 2 Mpbs up.
  • Max clients on a single AP during peak hours around 30, concurrent around 20

Thanks

4

Have you checked that there is no traffic among the clients?
It doesn't have to be necessarily towards the internet.
Iptraf could help you there.

1 Like
5

I use an Archer C7 v2 with 19.07.4 and have exactly the same issue. After some time a Dell 7300 laptop is reduced in download speed to about 20Mb/s after some time, while an iPhone has full wifi speed simultaneously. Reconnecting the laptop restores the wifi speed.

There are no other devices connected and no fancy VLAN's or extra SSID's. Only the AC radio is turned on. The device acts as an access point, not a router. Were you able to resolve this issue?