Hi @blade, this is impressive, you have done a lot of tests here!
I’d suggest you to upgrade to firmware 8.1.0 RC 1, because the new SpeedFusion chart will show a lot more information, and also we have a new SpeedFusion algorithm “Dynamic Weighted Bonding” which is designed for Cellular connections and may perform differently compare to the default bonding algo:
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Also, for me to get a better understanding of your environment the best way is by enabling Remote Assistance (RA):
With RA enabled, Peplink team (including me) will be able to access your device remotely and do some tests and apply configuration change to it. Is this possible for your case? After enabling RA, you can either send me the Serial Number using direct message (don’t post it in public forum post), or create support ticket here then I’ll follow up:
https://ticket.peplink.com/ticket/new/public
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And if possible, I’d like to see how it perform when you test with WAN Analysis tool using one Cellular WAN at a time, and both Cellular WAN simultaneously, test mode using TCP is fine. Looks like both LTE is on the same ISP, and and it’s possible a single Cellular already consumed all the available bandwidth on the cell tower side and thus using both WAN together doesn’t give any benefits.