SpeedFusion TCP traffic

I’m curious as to if any other users have seen this, or if this is something that Peplink is aware of. My setup is a Max700 with a Verizon LTE and ATT LTE connection. This is connected by SpeedFusion back to a Balance 380, with a 10 Mbps upload.

When running the SpeedFusion test from the Max700, the maximum upload speed I’m able to reach is 3.6700 Mbps with TCP traffic. That is using each of the modems together over the VPN. I’ve verified they are similar latency (within 50ms) and each alone is capable of 10 Mbps up (Verizon) and 6 Mbps up (ATT) when alone and out of the tunnel.

The second test I did was the same upload of TCP traffic from the Max700, but just using the Verizon connection through the tunnel. Same issue, max of 3.6700 Mbps. I also did this with ATT and saw the same number when over the tunnel.

Final test was from the Balance 380 side. I did a download test on the SpeedFusion tool, TCP on the VPN… max download was 3.6700 Mbps.

Question being, has anybody else seen this or have a fix/explanation? I have a application that relies on upload speed of RTMP traffic, which is TCP, and this 3.6700 Mbps limitation is KILLING the purpose of this bonded connection!


A support ticket has been created in our system for this issue.


I have a few people that are looking at 700’s for large deployments but have seen similar results with this traffic. Could you provide an update if there is any planned solution for this?

Thanks for the update!

Hi Kevin,

The SpeedFusion test tool doesn’t necessarily show the total amount of bandwidth available across the tunnel, it is a just a quick test to show the general health. I suggest to do some actual file transfers between the two networks, try transferring 3 different large files at the same time. You can also try with UDP traffic and disable the 256 AES encryption as well.

Cellular bonding is very tricky due to the inherent nature of these connections. Available bandwidth, signal strength, latency, noise levels, etc. can fluctuate from second to second and can have an impact on performance. No two installations are the same.

1+1=2 does not always hold true when bonding cellular connections, this is because the ‘1’ is not a static number with a guaranteed bit rate. These are dynamic bandwidth connections and always will be IMO.

We also have to remember that we are sharing the same available bandwidth with a plethora of Smartphone users out there, and the traffic coming from these devices is extremely bursty in nature. The carriers deploy ‘time slicing’ and other techniques on their networks so that ANY device connected to a particular tower will have immediate access to some of the available bandwidth at any given second in time. These are heavily contended networks…

On the other hand, SpeedFusion bandwidth bonding on T1’s and other similar types of land-line connections works extremely well and is very consistent all the time.

Instead of focusing solely on cellular bonding, let’s not forget that one of the most powerful features of SpeedFusion is the UNBREAKABLE VPN aspect of it using two or more connections from different providers. The ability to have an existing IPsec tunnel, VoIP call, file transfer, video-stream, etc. NOT break due to any single connection outage is amazing and powerful!

After all, if it’s good enough for our own Government and Military to use - it should be good enough for the average user. :smiley: