One site with an Untangle NG firewall v16.3.2 is having problems with SIP trunk phone lines. I am seeing the Analog Telephone Adapter (ATA) line statistics show what seems to me to be high packet loss (58733 out of 299556). The SIP phone line provider is telling me to increase the UDP timout in the firewall.

"Here are the most important settings:
-Set UDP timeout to 300
-Turn off SIP ALG
-Open all traffic to/from the PBX
-SIP transformations off
-Static NAT on

Ports to open:
UDP 5060, 5160
UDP 10000-20000
TCP 2001, 2002, 2003, 2005, 2006 & 58080

Sonicwall specific:
Access Rules LAN to WAN <--- Set that UDP Timer to 300 (Global timer will not fix this)
When you create an access rule for the PBX, it should be ANY port to ANY destination from source IP of <ip>
Please place that rule high on the priority list, and in the advanced tab of the rule, there should be a
UDP timer for that specific rule. This rule should be in the WAN -> LAN meaning inbound traffic from the
internet coming into your network. The UDP timeout of the rule for the PBX needs to be 300 seconds ideally.
The phone and PBX will be able to stay in communication when you have this rule into place with the specified
timeout on the specific rule. If you change only the global timeout, it does not always change it for all the
rules already created."

I have created a couple bypass rules, one with the source IP address of the Analog Telephone Adapter (ATA) and another with the destination IP address of the ATA. I also disabled "Enable SIP NAT Helper" in Config > Network > Advanced > Options. I have setup QoS with the proper network bandwidth and added a QoS rule to set the priority to Very High for the ATA source IP address and one for the destination IP address. I added a Threat Prevention pass site for the SIP vendor's registration server (by hostname).

I have read the Wiki on VoIP ( as well as the VoIP Deployment Models and Troubleshooting Guide ( and believe that I have done everything in those documents.

I have not found anywhere that I can change the UDP timeout. How can I change the UDP timeout?

Is there anything more I need to do?