if you set it in your modem then your modem is not in a bridged mode. That
also means you have 2 active routing/nat and port aware elements, which is
not a good idea.
I'd suggest setting your modem to bridged mode and putting your public ip
address on your firewall directly.
==
Last 2 day my colleague bring one Sonicwall back.. i know my nightmare
come true..
i base on this http://sipx-wiki.calivia.com/index.php/Firewall_Configuration
will know more about the port setting
but i still have some issue can ask for advice?
basically my network diagram is :
internet -
