We have several employees that work outside of our company that we would like to setup them up a CISCO 7940 phone for their home office. The phones work perfect in the office, and yes the phone has been converted to use SIP. Does anyone know how to setup these Phones to work in this way? We have a SonicWall as our firewall in the office running the Enhanced OS, and I have opened all UDP Ports stated in the 3CX Console General Settings area. However it just will not work.