Digi TransPort WR31 User Manual page 418

Configure Virtual Private Networking (VPN)
local TCP/UDP port in the range of n1 to n2
Allow IP packets with source TCP/UDP ports in the specified range to be tunneled. This is only
available when IKEv2 is in use.
remote TCP/UDP port in the range of n1 to n2
Allow IP packets with destination TCP/UDP ports in the specified range to be tunneled. This is
only available when IKEv2 is in use.
Digi TransPort WR Routers User Guide
IPsec parameters
418