The following is how I have my Sipura configured. Note that I am behind NAT and am not using the fwdnat.pulver.com proxy. The following configuration should work provided you've mapped the following ports on your NAT device to point at your Sipura:
(Note that you can use port 5060 instead of port 5062, I happen to also have a BroadvoxDirect Sipura behind the same NAT, which also uses that port).
Since my NAT device is a Linux box running iptables, I can give you the exact commands I use:
linux# iptables -t nat -I POSTROUTING -s sipura_ip -p udp --sport 5062 -j SNAT --to external_ip linux# iptables -t nat -I PREROUTING -d external_ip -p udp --dport 5062 -j DNAT --to sipura_ip:5062 linux# iptables -t nat -I PREROUTING -d external_ip -p udp --dport 16384:16391 -j DNAT --to sipura_ip:16384-16391 linux# iptables -I INPUT -d external_ip -p udp --dport 5062 -j ACCEPT linux# iptables -I INPUT -d external_ip -p udp --dport 16384:16391 -j ACCEPT
Here are the two screens that are important. I've also included some of the other settings like Dial Plan and Codec settings:
