Good.. I'm allworx certified engineer.
Sonic wall Tz170 is fine.. But just make sure allworx has WAn and LAN port..
Allworx Wan side shoud have public IP assigned and Must be outside of your firewall.
Lan port will be in your network. So all works shouldn't have any problem.
Often issues with sonicwall is outbound voice.. So make sure you open ports fot SIP
and other voice channels. Also we do not recomment using AT&T U-verse foir highspeed
internet. U-Verse it self utilizing some of port the SIP devices are using..
Allworx is pretty simple to deploy and very nice system for mid-size and samll business..