VoIP SIP trunk - incoming packet dropped "connection to be closed"

janjezek · January 2022

Hello everyone,

we have outgoing calls via SIP trunk working but incoming calls are dropped. In the packet monitor, the reason is "Packet dropped - connection to be closed". I run into this error on yet another location, another firewall, another provider, so I am curious what that could be. In the knowledgebase I haven't found neither helpful explanation of this error, nor troubleshooting steps.

SonicOS 6.5.4.8/6.5.4.9, NAT consistency Off, SIP transformations Off

Any advisory/idea would be highly appreciated.

Cheers,

Jan

Nevyaditha · January 2022

Hi @janjezek ,

Can you please confirm the NAT Policies are set up appropriately on the firewall for the inbound call flow?

https://www.sonicwall.com/support/knowledge-base/how-to-configure-voip-to-use-any-voip-phone-system-best-practices/210615132522720/

https://www.sonicwall.com/support/knowledge-base/common-mistakes-with-port-forwarding/200530122019613/

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VoIP SIP trunk - incoming packet dropped "connection to be closed"

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