High Ping, High Packet Loss with UDP Streams

Hi folks!

I use the latest and greatest release OpenWrt 18.06.1 r7258-5eb055306f on my TP-Link TL-WDR3600 v1 with Atheros AR9344 rev 2.

Besides some problems with 5 Ghz which had some DFS problems I had no problems with it.

The Ping to the Device from my MCB is 1-2ms. But when I play NVIDIA GeForce Now I have some random ping spikes and losses. Also the NVIDIA client always reports high packet loss.
Every Speedtest reports 50/5

$iperf -c ping.online.net
Client connecting to ping.online.net, TCP port 5001
TCP window size:  129 KByte (default)
[  6] local port 55010 connected with port 5001
[ ID] Interval       Transfer     Bandwidth
[  6]  0.0-10.1 sec  5.50 MBytes  4.56 Mbits/sec
$iperf -u -c ping.online.net
Client connecting to ping.online.net, UDP port 5001
Sending 1470 byte datagrams, IPG target: 11215.21 us (kalman adjust)
UDP buffer size: 9.00 KByte (default)
[  6] local port 62120 connected with port 5001
read failed: Connection refused
[  6] WARNING: did not receive ack of last datagram after 1 tries.
[ ID] Interval       Transfer     Bandwidth
[  6]  0.0-10.0 sec  1.25 MBytes  1.05 Mbits/sec
[  6] Sent 892 datagrams

Same problem with another Wifi with pfsense. But when I connect my macbook via lan to the switch everything is fine. Wireshark only reports wrong checksums which is normal. Booth wifis are on the same switch with the same vlan.

TL;DR: Any ideas how to debug why udp is slow over wifi but not pover lan and TCP has no problems?

How large are the spikes on WiFi?

It ranges from 100ms up to 999 or a timeout :slight_smile:

My idea was to play a bit with the vlans. I wrote something on the ubnt forums might be a/the case.

Thanks for your help!

You noted this occurred on a pfsense device as well...does your location have congested 2.4 GHz WiFi?

Not at all. 5 Ghz is nearly empty and does not overlap.