This is the Sonicwall Enhanced OS but the Standard OS should have a similar page. The box for ENABLE SIP TRANSFORMATIONS needs to be un-checked. It is checked by default.
Additional notes for Sonicwall Firewall setup:
If the customer is using the Sonicwall “Enforced Client Anti-virus” they must exclude the Ipitomy box and phones in the Sonicwall settings, otherwise these will be blocked because the Sonicwall will want them to install anti-virus, which of course, they can’t do because they’re phones, not computers.
Enable Consistent NAT should be checked.
This is the Sonicwall Enhanced OS but the Standard OS should have a similar page. The box for ENABLE SIP TRANSFORMATIONS needs to be un-checked. It is checked by default.