I had an issue yesterday when my PAPT2 failed to reregister after I rebooted my router. I submitted a ticket, the response was prompt, and they enabled a STUN server and set NAT keep-alive packets to be sent every 5 minutes to help prevent the problem from happening again. They also recommended that I disable the SPI firewall on my router because it may cause intermittent problems, even if it seems to be working.

I rebooted the router again today, and when the PAPT2 again failed to register (with the SPI firewall still on), I experimented a bit with putting the PAPT2 in a DMZ vs. turning off the firewall completely. As far as I could tell, the DMZ did not let it reregister, but shutting the firewall off did.

I'm not crazy about leaving the firewall off, but I suppose I could use an iptables-based firewall instead of the SPI firewall (I am using DD-WRT firmware). I'm just wondering if others out there have thoughts & experience on the pros & cons of an SPI firewall and other router security measures while using VOIP.

Thanks.