Sonicwall Firewall - SIP Transformations
Firewall => Advanced => Scroll down to "UDP":
Increase UDP timeout to 120
VOIP => Settings:
o Turn on Consistent NAT.
o For customers using the Junction Networks SIP Hosted PBX service and the Sonic Firewall, the SIP Transformations sections should be DISABLED (unchecked).
Note: Junction Networks actually uses the packet header IN CONJUNCTION with the internal IP address inside the SIP packet to determine optimal settings, so we need both.
Additional step:
Firewall => Access Rules:
Add an 'Access Rule' for any traffic from WAN Network 66.227.100.0 Netmask 255.255.255.0 to the LAN. (shown)
Add an 'Access Rule' for any traffic from WAN Network 199.7.173.0 Netmask 255.255.255.0 to the LAN. (not-shown)
Add an 'Access Rule' for any traffic from WAN Network 199.7.175.0 Netmask 255.255.255.0 to the LAN. (not-shown)
*DISREGARD* the following notes from Sonic...
http://help.mysonicwall.com/sw/eng/general/ui1/6600/Access/Services.htm
Enable SIP Transformations - Select this option to transform SIP messaging from LAN (trusted) to WAN (untrusted). You need to check this setting when you want the SonicWALL to do the SIP transformation. If your SIP proxy is located on the public (WAN) side of the SonicWALL and SIP clients are on the LAN side, the SIP clients by default embed/use their private IP address in the SIP/Session Definition Protocol (SDP) that are sent to the SIP proxy, hence these messages are not changed and the SIP proxy does not know how to get back to the client behind the SonicWALL. Selecting Enable SIP Transformations enables the SonicWALL to go through each SIP message and change the private IP address and assigned port. The Enable SIP Transformation also controls and opens up the RTP/RTCP ports that need to be opened for the SIP session calls to happen. NAT translates Layer 3 addresses but not the Layer 5 SIP/SDP addresses, which is why you need to select Enable SIP Transformations to transform the SIP messages. It's recommended that you turn on Enable SIP Transformations unless there is another NAT traversal solution that requires this feature to be turned off. SIP Transformations works in bi-directional mode and it transforms messages going from LAN to WAN and vice versa.
Sonicwall Router causes Jitter
After many hours of troubleshooting and phone calls, we found that our sonicwall router was causing jitter and breaking up calls with our customer. Either bypass this router completely or use a different router if you are having jitter. Also try the jitter test from Onsip to see if jitter is the cause.