ISP seems to be throttling Wireguard (Hong Kong)

Hi all.

I’ve been sitting on this for a few months now, but I’d just like to get word out about this in case it’s not a isolated incident. I wasn’t sure where to post this, but Tor Project forum seemed like a great place. (I genuinely don’t know where to post this. Perhaps it’s just the ISP being garbage.)

Regardless, enough fluff.

ISP: Netvigator/網上行 (residential)

Recently, I’ve been experiencing ISP throttling whenever I am connected to a Mullvad Wireguard server over UDP. Regardless of port, sever location, or even connection duration, I get throttled to around 150Mbps; and there seems to be some sort of traffic prioritize making my traffic “low priority.”

Speedtest results

I ran each speedtest twice, over the course of a week, over wired Ethernet. Once at 08:00, once at 20:00. These are the averages.

I pay for a 1Gbps connection.
Without VPN: 980Mpbs down, 890Mbps up.
With VPN (connect to HKG Mullvad servers; Wireguard UDP): 120Mbps down, 130Mbps up.
With VPN (connect to HKG Mullvad servers; Wireguard TCP): 660Mbps down, 520Mbps up.

Does this mean anything? Maybe.
Could it be a crappy ISP messing with traffic? Potentially.
Is this part of a bigger censorship event? Unlikely, but still possible.

I’m unable to test if the Tor protocol is being throttled due to the inherent slowness of the Tor Network. But the fact that Wireguard appears to be throttled is a red flag imo.


Hi, I’d recommend publishing your findings at Net4people BBS: GitHub - net4people/bbs: Forum for discussing Internet censorship circumvention. It’s a very active community and you might get more reports from your region.

Back in 2021, some users from HK reported having issues with their VPNs and Tor. [Hong Kong] Ask volunteers to run emma (#40029) · Issues · The Tor Project / Community / Support · GitLab.


Some modems/routers don’t use Hardware Acceleration for UDP.
That can look similar like being throttled.

If you can check CPU load of the modem/router and it’s close to 100% during your tests then that may be the reason.

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