I’ve used SpeedFusion Cloud several times in various locations and scenarios in the past couple months and have not had good results any time. Thinking it might have something to do with the SF Cloud I tried a test with just a VPN connection between devices. I’ll detail this setup below as I look for insight and hopefully resolution of the problem(s).
PepVPN link between a UBR_LTE and Balance 20x.
Firmware 8.1.2 build 5054
2 WAN connections: One Verizon sim in the UBR and a T-Mobile Home Internet modem that is wired with ethernet to the WAN port of the UBR.
Verizon download is typically 8-12Mbps
T-Mobile Home Internet download is usually 10-25Mbps but sometimes even higher.
Firmware 8.1.2 build 5025
A single WAN connection from a cable modem.
Download is typically over 150Mbps
Upload is usually solid at about 18Mbps.
Results of file transfer:
SpeedFusion (both WAN active) = download speed between 500Kbps and 3Mbps
Verizon only (with VPN still enabled) = download speed 3-8Mbps
T-Mobile only (with VPN still enabled) = download speed 5-15Mbps
I connected from a computer at the UBR end to a computer at the B20x location and copied a 59MB file back to the UBR computer. While watching the Status->Speedfusion page in the UBR Web Admin I watched the speeds of the two internet connections.
Initially I had all the stock settings for the SpeedFusion VPN.
Bandwidth limit off
WAN Smoothing off
Forward Error Correction off
Receive Buffer 0ms
With these settings I found that the Verizon connection was being largely favored and in fact, the T-Mobile connection was often showing latency of over 1000ms at which time it seemed like the speed would drop to <1k. So I tried adding some Receive Buffer.
Setting the receive buffer in the UBR to 20ms and the same in the profile for the UBR connection in the B20x I found the latency settled down. Latency for both connections typically ran between 35 and 70ms and the throughput was more balanced. Still, I never got speed even close to only using one or the other connection by itself.
I did not see indication of packet loss with the final settings (not sure about when the Receive Buffer was 0). The CPU load gauge of the UBR (on the Dashboard) during the file transfer generally hung around 50% or below.
Shouldn’t I see something in the range of 15Mbps with both internet connections active? Why does it drop so badly when they are both working?