This module matches on UDP-specific fields.
.TP
.BI "--orig-port-src " "PORT"
Source port in original direction
.TP
.BI "--orig-port-dst " "PORT"
Destination port in original direction
.TP
.BI "--reply-port-src " "PORT"
Source port in reply direction
.TP
.BI "--reply-port-dst " "PORT"
Destination port in reply direction