Inconsistency with hardware/software versions:
The Sonicwall router/firewall has many revisions/versions, including the Standard OS and the Enhanced OS. Due to the amount of revisions and versions, Nextiva has found the Sonicwall to be inconsistent in how it handles Nextiva VoIP traffic.
Sonicwall Standard OS:
The Standard OS seems to frequently have issues with blocking/disallowing traffic that should normally be accepted. This version of the Sonicwall is not recommended or supported.
Sonicwall Enhanced OS:
The Enhanced OS seems more consistent and reliable than the Standard OS, but there have been a few revisions of the Enhanced OS that have similar problems as well. This version of Sonicwall is not recommended, but in many cases is supported.
Using Sonicwall With Nextiva:
Nextiva recommends that the phones are connected to a Linksys WRT54GL or a Netgear WNR3500L v2 with custom Tomato firmware to allow for consistency and ideal bandwidth allocation. In many cases, connecting phones to a router with Tomato and connecting the rest of the network devices to the sonicwall can be accomplished. It is important that the router that the phones are connected to (with Tomato firmware) is directly connected to the modem.