# Your inet interface
ext = de0
int = de1

# SIP (TCP)
voip_tcp = "5060:5063"
# SIP, IAX2, IAX, RTP, MGCP (UDP)
voip_udp = "{5060, 10000:20000}"


nat on $ext from $int:network to any -> ($ext)
rdr on $ext proto tcp from any to any port 22 -> 172.16.0.3
rdr on $ext proto tcp from any to any port $voip_tcp -> 172.16.0.3
rdr on $ext proto udp from any to any port $voip_udp -> 172.16.0.3

pass in on $ext inet proto tcp from any to any port $voip_tcp flags S/SA keep state
pass in on $ext proto tcp from any to 172.16.0.3 port 22 flags S/SA synproxy state
pass out on $ext inet proto tcp all flags S/SA keep state
pass in on $ext inet proto udp from any to any port $voip_udp keep state
pass out on $ext proto udp all keep state