Strange Wireguard (possibly) issue

[jp141]

Hi Everyone,

I am having a strange issue with Wireguard, first a bit about my setup:

Im using a Dell Poweredge T110 II with the following:

Intel(R) Xeon(R) CPU E31270 @ 3.40GHz (should be more than enough grunt)
8 CPUs: 1 package(s) x 4 core(s) x 2 hardware threads
AES-NI CPU Crypto: Yes (active)
8gb RAM
Genuine Dell INTEL I350-T4 PCI Express card using standard igb drivers
900 meg down and 900 meg up PPPOE FTTP connection
5 x Wireguard VPN connections/interfaces to my VPN provider Airvpn:

All network offloads enabled and some additional tuning system tunables set:



Without the VPN I am able to download a consistent 117.6 MB/s (35% CPU) for long periods of time without any drops etc however when I enable the VPN connections I am able to get a consistent 112.6 MB/s (250% CPU) which is great allowing for the VPN overheads etc

However after approx 5 mins with the VPNs at full tilt my connection will nosedive to about 10 MB/s for about 5 mins then go back to normal full speed.

Are there any buffers I should be looking at? I am suspecting the VPN provider or ISP may be doing some sort of throttling for a shot time and as it doesnt happen without the VPN I am leaning towards the VPN provider AIR VPN but I dont think they apply any traffic management so it could be a Wireguard issue/buffer thats filling up?

Does anyone have any ideas or things I should check?

Thanks :)

Apologies if this is in the wrong forum section admins please move if required.