High latency observed over the SpeedFusion VPN. Where to start with monitoring?

Hello experts,

one of our customer is using a SpeedFusion VPN between two Peplink Balance 210 Routers.

When configuring the SpeedFusion VPN a few months ago, we specified (for each Peplink Balance Router) the highest priority for a DSL-based land-line connection. Both land-line connections are from the same provider and have the same data bandwidth values in both directions and are used exclusively in making the SpeedFusion VPN.

Today the customer complained about sluggish performance of Remote Desktop over SpeedFusion VPN despite QOS for RDP.

Looking at SpeedFusion Status on one of the devices, we noticed very high latency over the SpeedFusion VPN (please see the screen capture below).

Ping and latency tests of each connection from an external core router seemed fine in general.

What would you suggest to use in order to more effectively monitor the actual transmission quality of each WAN link (e.g. increasing the continuous ping packet size, using specific monitoring tools such as SNMP etc.) ? I am not 100% sure if the provider is rate limiting SpeedFusion VPN traffic at given times, so I would like to start monitoring key SpeedFusion VPN and WAN links parameters in order to narrow down the possible causes.

Any help would be greatly appreciated.

Thanks and Regards,


A latency issue could be caused from either side and you can build the SpeedFusion VPN with individual WAN links to help narrow this down. If you think the ISP is rate limiting UDP 4500 traffic, you have the ability to change the data port used within each VPN profile.

Hi Ron,

first of all thank you for taking the time to reply to my question.

Because we are also observing a high packet drop rate over the SpeedFusion VPN, I have just opened up a support ticket for the issue so we can better into this.