Introducing Forward Error Correction (FEC)



Available from firmware version 8.0 for Peplink routers with a SpeedFusion WAN Smoothing license.


When using multicast applications on lossy WAN connections the performance can suffer.
To overcome these problems Peplink introduced WAN smoothing, but WAN smoothing has an overhead of at least 50%.
This is not always desirable when there isn’t enough bandwidth available.
Peplink has therefore introduced Forward Error Correction in Firmware 8.0
FEC is a cousin of WAN smoothing but it consumes less data.
It is useful for bandwidth sensitive applications such as mobile streaming.

When to use:

Forward Error Correction
Bandwidth sensitive 1-way communications like live TV and video streaming.
WAN Smoothing
Latency sensitive 2-way communications such as VoIP or Video Conferencing.

FEC definition

Forward error correction (FEC) is a digital signal processing technique used to enhance data reliability. It does this by introducing redundant data, called error correcting code, prior to data transmission or storage. FEC provides the receiver with the ability to correct errors without a reverse channel to request the retransmission of data. It is required that the peer router is using Firmware 8.0.0 and above.

Configuring your Peplink router

In the web admin interface go to
Network > Speedfusion on your Balance router or
Advanced > SpeedFusion on your MAX router.

Select a “New Profile” or open an existing PepVPN profile.
Select the option of choice on the Forward Error Correction drop-down list.
Save and Apply the changes

The options are:

Off Default
Low Expected Overhead 13.3%
High Expected Overhead 26.7%

Its really speedfusion bonding can bonding bandwidth?

This. Is. Amazing! Good work!

Now all I need is some proper crappy WAN links to test this on :wink:


Come on over here … I’ll lend you some! :woozy_face:

crappy WAN links


Very impressive feature!
With FEC set to “High” moving UDP/RTP over dual bonded LTE with almost no errors (!!)
Without FEC, video looks like slideshow, which is expected when moving UDP/RTP over public networks.
Wow! Thank you!!


Did you try with the Medium setting, which I guess compares 1/3 against 2/3 FEC overhead.


There is no Medium setting at the moment, in firmware 8 beta 3, the overhead of FEC (Low) is 13% and FEC (High) is 26.7%:


Sorry I meant the lower FEC setting. I need to upgrade central Hardware before I can try.


Good information with Forward Error Correction in Real-time Video Streaming Applications.