I had have encountered the Speed Fusion VPN issue.
After I created the SpeedFusion between Device A & B with WAN1 Link, everything went well.
I monitored the Physical interface & VPN traffic with PRTG tools.
The WAN upload and download maximum speed is 20M/20M(Device A) & 15M/15M(Device B).
I found the traffic about WAN1 is well, but the VPN traffic is wired.
The PRTG shows that WAN1 traffic is in normal range(within 20M/20M), but the Speed Fusion VPN sometimes would exceed the traffic up to 100Mbps.
Model: Peplink 580
Firmware: 6.3.1 build 1631
WAN1: Download: 20Mbps, Upload:20Mbps
Model: Peplink 380
Firmware: 6.2.2 build 3362
WAN1: Download: 15Mbps, Upload:15Mbps
How could I fix this problem?