Does Speedfusion overdrive WAN connection and causes packetloss?

Speedfusion graph shows packetloss at the maximum offical upload capacity of the connection when a LTE CAT12 modem is the only WAN in use, but p2p WAN analysis using that WAN against the same Fusionhub doesn’t.

Speedfusion Graph showing packetloss:

Speedfusion Graph with upload limit of 35 MBit/s not showing any packetloss:

WAN analysis with the same link with 50 MBit UDP not showing any packetloss:

Some further WAN analysis tests:

  • sometimes I see some packet loss at 50 MBps (probably there was some other traffic on my network in parallel).
  • I have never seen any packet loss at 49 MBps.
  • I see a lot of packet loss at 60 MBps.

Subscription is standard LTE/LTE-A (CAT4/CAT6) provider with official 50 MBps upload.

Assumption: SpeedFusion tries to send with higher bandwidth than the limit of the WAN connection.

Concern: This type of packetloss might influence negativly the connection performance and might misslead the load balancing algorthm and can degradate the overall bonding performance. This type of packetloss might be also harmless - but still missleading during troubleshooting.
Clarification would be apretiated.

This is a breakout of topic: LTE: speedfusion is slower than the fastest link in the bonding?



Lets ask @Steve if he has any idea why the Speedfusion graph shows packetloss when the CAT12 modem is the only WAN in use, but p2p wan analysis using that WAN against the same Fusionhub doesn’t.

Also - the latest firmware (8.1.0RC1) has much better speedfusion graphing and is probably worth installing at both ends. Firmware 8.1.0 RC 1

Hi @blade,

When a WAN connection is congested (50Mbps in your case), packet loss is absolutely normal and this kind of packet loss is just a congestion event, because the TCP protocol will keep trying to increase the throughput until the link is congested.

Compare to the WAN Analysis result, because you are using UDP to test the WAN with static traffic throughput, it will never be congested and thus no packet will be loss.

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Thanks a lot for the clarification! So these packet losses are just normal during the WAN connection is at its maximum bandwidth capacity.

One a side note: these packetlosses cause confusion during troubleshooting.

dear steve,

in my case, i have peplinks in two sites, 1 site has two 100Mbps links and the other has two 30 mbps links, however, i can see a huge packet loss with the traffic reaches 10 mbps, how can i increase the limitation on the pepvpn to 30mbps instead?!

Hi @amjad.kiwan, the 30Mbps bandwidth advertised by your ISP is not always true when you are connecting to other ISPs or to other countries. If you see packet loss when throughput reaches 10Mbps, it can be your ISP’s infrastructure is congested and losing packets. SpeedFusion support FEC (Forward Error Correction) to overcome packet loss, but there is limitation if the loss rate is too high, as you said huge loss rate I’m not sure what’s the exact loss rate is.

If you want our team to look further, please create a support ticket so we can follow up with you:

thanks steve for your response, however, i meant by huge packet loss is that between 40-50% and FEC can support up to 26% , also i have checked the link speed and even changed one ISP of the two suspecting to have the problem but still the same, also, before installing peplink balance 580 i was using site-to-site vpn on my firewalls and it was very normal when exceeding the 10 mbps speed.

i will open a ticket thanks for sharing the links, looking forward to look into my problem shortly.

@amjad.kiwan, we shall follow up with you in the ticket. Fyi, IPSec VPN uses IP protocol 50/51 while SpeedFusion is using UDP 4500. So, there is a possibility the Qos from the ISP may treat these 2 protocols differently.

thanks for your follow up, i’m not sure about how our ISPs treating these ports, however, this is a good idea and i will send them to prioritize this port and see.

I’d really like to be able to limit speedfusion bandwidth per WAN, as far as I know Speedfusion doesn’t use the bandwidth figures set on a WAN.

I noticed setting the overall bandwidth limit on the tunnel just below the WAN’s combined bandwidth does help somewhat but even then you get Speedfusion hitting packetloss and backing off.

For cellular it’s going to be a shot in the dark but for fixed line connections providing the ISP’s are half decent they generally hit whatever speed they’re sold as, but trying to shove 40Mbit/s down a 30Mbit/s lines never going to work.

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