SpeedFusion debug for link issue

The setup in question is as follows:

MAX HD2 with two wired WAN connections and two cellular connections. SpeedFusion tunnel to a FusionHub appliance in my datacenter on the other end.

My desired configuration is to have the SpeedFusion tunnel set up with:
WAN 1 = Priority 1
WAN 2 = Priority 1 (e.g. equal to WAN 1)
Cellular 1 = Priority 2
Cellular 2 = Priority 3

The issue that I am having is that WAN 1 appears to have some kind of network issue that prevents the tunnel from performing properly. If I set WAN 2 and Cellular 1 as Priority 1, I see SpeedFusion traffic moving in both directions over both links.

If I set WAN 1 and WAN 2 to Priority 1 and then push data while monitoring SF traffic, I see traffic moving in both directions on WAN 2. On WAN 1 the traffic is minuscule in the downstream direction but normal in the upstream direction.

If I set WAN 1 as the only Priority 1 connection, the SF tunnel establishes and I can run small packets over the link (e.g. ping, DNS lookups, etc.) but TCP is completely non-functional.

I have tested WAN 1 manually to confirm that the MTU is 1500 and 1500 byte packets with the DF bit set will pass all the way through to my FusionHub appliance. I have also tried reducing the MTU just in case there was something odd happening specific to the SF traffic. No change.

I’m sure that this is an issue with something on the WAN 1 network, but I am in need of some further debugging/diagnostic capabilities for the SpeedFusion tunnel in order to be able to formulate a support request to the carrier to try and get it resolved. Is there some diagnostic function that can be run and/or debug logging that can be enabled on both ends of the SF tunnel to identify specifically what is happening?

The tools to use for SpeedFusion issue resolution are:

WAN analysis (System > Tools | WAN Analysis) set Fusionhub as the Server and HD2 as the Client) - used to test raw bandwidth availability per WAN link outside of SpeedFusion between the HD2 and FusionHub. This tool often highlights ISP related issues - especially as you can test bandwidth using multiple WAN links at the same time.

SpeedFusion Speedtest Tool (Status > SpeedFusion | (Profile)image button.
This lets you push and pull bandwidth over the tunnel whilst turning WAN links on and off to see what happens. You can also test with TCP and UDP traffic

SpeedFusion Graphs (Status > SpeedFusion | (Profile)image button.
This shows rel time per tunnel bandwidth latency and packet loss info when you’re running SpeedFusion bandwidth tests.

First test the wan to wan bandwidth (upload and download) so you know what is actually usable between you and the FusionHub on each WAN link.

Then open the SpeedFusion Graphs in a new tab.

Then run multiple SpeedFusion Speed Tests and screenshot the Graphs. Then post back here for review.

Or log a ticket and ask for help from Engineering.

1 Like

Thanks for this info – it was very helfpul.

On the WAN analysis side I am able to achieve the full bandwidth (or close to it) of both WAN links, including simultaneously.

Within SpeedFusion Speedtest tool, the initial performance is fine (both WAN links are used). After a short while, the second WAN link no longer passes traffic – it always reads < 1kbps. There isn’t excessive packet loss shown, it’s as thought it just doesn’t attempt to pass any traffic over that link.

Even while that was happening, the WAN analysis test would show full performance of the troubled WAN link.

Still believe it was a provider issue, as a test I re-configured the troubled WAN link as GRE mode and had it immediately establish a GRE tunnel to my router that sites next to the FusionHub appliance. I have been running that way for 2 days now and the SpeedFusion tunnel has not stopped working in that time. I believe that the WAN provider of the second link is doing some kind of aggressive timeout of traffic within their network. The SpeedFusion tunnel established inside of GRE seems to sidestep that issue. Although less than ideal (it would be nice to build the GRE tunnel and only have the SpeedFusion traffic ride inside of that tunnel instead of everything that passes over that WAN link), it works so I’m going to continue with this configuration for a while.