If Balance/MAX unit is placed behind a firewall, you would need to define the firewall rules and inbound port forwarding policy on firewall unit for the following port numbers in order to allow SpeedFusion traffic passing across the firewall.
SpeedFusion uses TCP port 32015 and UDP port 4500 for establishing the connections by default.
Note on Data Port:
This is the outgoing UDP port number for transporting VPN data.
By default, UDP port 4500 will be used. Port 32015 will be used if the remote unit uses Firmware prior to version 5.4 or if port 4500 is unavailable.
You can use a custom port number if the [Custom] option is selected, an outgoing port number range from 1 to 65535.
Also, if you have configured and active [IPsec VPN] or [L2TP with IPsec] profile on the Peplink router, then UDP port 4500 will be occupied and SpeedFusion will use next available port (UDP 32015).
When using multiple tunnels between 2 locations (when using Outbound policies within a PepVPN or Speed-fusion tunnel) multiple ports are in use (1 for each-subprofile).
The UDP data ports used when using are:
4500, 4501, 4501, etcetera or (when port 4500 is in use by IPSEC or L2TP) 32015, 32016, 32017, etcetera.