Balance 2500 – Total WAN drop when enabling SpeedFusion FEC on single tunnel (8.5.3 build 5403)

General
1

Hello Peplink community,

We experienced a critical issue with a Peplink Balance 2500 during a live production, and I’m looking for help troubleshooting or confirming whether this is a known bug.

Setup

  • Device: Peplink Balance 2500
  • Firmware: 8.5.3 build 5403
  • Use case: Live show / broadcast environment
  • SpeedFusion tunnels: ~15 active SpeedFusion connections
  • WANs: Multiple active WAN connections (stable before incident)

Issue

While enabling SpeedFusion FEC on only ONE of the existing SpeedFusion tunnels , the Balance 2500 experienced a total WAN drop :

  • All WAN connections went down simultaneously very brief, video stalled for a second
  • All SpeedFusion tunnels stayed connected
  • Traffic was fully interrupted for a very brief moment

This behavior is unexpected — applying FEC to a single SpeedFusion profile should not cause a global WAN failure.

The timing was immediate after applying the FEC setting, strongly suggesting a correlation.