We've recently been experiencing extremely slow VPN and Wifi throughput on our Vigor 2962.

We have also tried using a Vigor 2952 and are getting the same problems.

The VPN speed in around 30Mbs, whereas the LAN is 10 times that.

Likewise we are getting similar speeds on the wifi through the VigorAP912C access points (which are running as a mesh).

Since this is affecting both VPN and Wifi I wonder whether you have any ideas what could be the cause.

I've carried out the checks here -  What to do if the NAT/ VPN Performance is lower than expected? | DrayTek  but with no improvement.

I've also checked the MTU and lowered but no improvement.

If anyone has any additional ideas that would be appreciated.

Thanks
Carl

Might be a daft question but do you have any QoS or bandwidth management configured on the router?

No I switched all of that off, we actually factory reset the router too just in case something was hidden. What I find odd is that the speeds we are getting for vpn and wifi are nearly exactly the same and represent 10% of the total bandwidth available.

I thought MTU but I've lowered it quite a bit and it's still not improving.

Perhaps your isp is throttling vpn speed

What VPN protocol are you using, SSL has always been on the slow side, at least on the 28xx series, IKE or L2TP have always performed better.

Yes I have tried both SSL and L2TP both are really slow.