Bonding is not work Between Two VSAT Links

Dear Friend !
i have a peplink balance 30 pro with 2 WAN link VSAT Connection Bandwith of each link 15mbps download and 1.3 upload
i create and bonding tunnel in my speadfusion cloud
but when I do speed test only I receive 1 links bandwidth
what is the issue of why bonding is not work in VSAT connection?

What throughput do you see if you use just one VSAT connection in the tunnel?

I suspect you might be seeing a side effect of TCP optimisation (Pre ACK) not working because your TCP traffic in the tunnel is encrypted.

One way to get round this might be to expose the TCP Sessions within the tunnel so that TCP optimisation can take place.

1 Like

There is a very old post I did here that mentions TCP Optimisation over vsat links that might be useful

1 Like

when i do speed test i received bandwidth of only one VSAT connection 11 mpbs
bonding is not work

Yes you said that.

If you only use a single VSAT connection with the VPN what speeds do you see?

1 Like

Tunnel is create between my peplink and SFC 11mbps
no VPN
i you want i can screenshoot my configuration

Ah ok, so SpeedFusion Cloud (SFC) is using SpeedFusion VPN.

Unplug one VSAT WAN, run speedtest via SFC, what do you get. Then plug 2nd VSAT back in again - what do you get on a speedtest with two?

1 Like

Dear Martin!
I unplug the WAN 1 VAST and do speed test i received 11mbps from WAN2
than i plug WAN1 and unplug wan 2 i also Receive 11mpbs
but when i connect both i must Receive at least 20 Mbps or 18 mbps from both links
which i not received

I can take a look for you if you like. Will PM you.

1 Like

Yes Of course
i can give you Remote access

OK interesting results here. Going to share to see if anyone else has seen this.
I enabled the Expose TCP headers option. In Speedfusion status, WAN links went from saying the latency was 1100ms to 1ms - so TCP pre ACK on the VSAT modems was working. Then SFC tunnel drops before I can test it. Then Balance shows as disconnected on IC2, but teamviewer session to PC on LAN works. then later, maybe 5mins, Teamviewer session crashes out too.

Only way to get the device back is to swap the two VSAT WANs over. Then it happens again.

Any ideas? Have advised that Aziz should download a diagnostic and log a ticket because that behaviour is weird. Almost seems like a country level VPN ban, but IC2 detected IP is in Pakistan.Do they block inter-country VPN in Pakistan?


Google search suggests it might…


VPN is working in Pakistan !

OK so not that.

Send the diag report to engineering Aziz, lets see what they say! Whatever is going on its very strange.

Good luck!


Ok Mr Martin Thank you so much for today support and effort
have a nice time bye …

1 Like

A couple of years ago we had a similar problem in the Middle East using a locally sourced set of vSAT connections, we could not get a stable SF tunnel and when we could get the tunnel up it would either perform poorly or drop after a couple of hours and not renegotiate for several minutes.

Along with the usual TCP ack hacks that are common in sat networks we suspected the provider was also messing with certain types of traffic (particularly ICMP and ESP) as well as several layers of NAT/PAT between us and the public internet.

I recall that we tried bringing SF up against multiple of our hubs in the region and wider world but nothing ever really changed, performance was either poor or the tunnel unstable.

In the end we had the ISP configure their modems to give us a direct public IP and bridged that through to the Peplink WANs and all the problems magically went away.

We never really got to the bottom of the root cause of the issue, but it could be worth investigating if your provider can offer a direct public address from the modem to you.

Just a thought though, @MartinLangmaid if Aziz is using SFC doesn’t that mean the SF tunnel encryption is always on, could be worth setting up a test hub in Vultr or somewhere and testing without the tunnel encryption to see if the provider are inspecting and manipulating the traffic based on the headers.