Changes
/* Network (@PTL) */
<pre>
iptables -t nat -A PREROUTING -p tcp --dport 5000 -j DNAT --to-destination raspi_internal_ip:5000
</pre>
<pre>
#ACTION    SOURCE      DEST                                   PROTO        DEST PORT
DNAT       net         loc:local-IP-address[:local-port]      protocol     port-number
DNAT       net         loc:raspberrypi                        udp          5000
</pre>