Since the update to XG330 (SFOS 19.0.0 GA-Build317) the VOIP software no longer works over the VPN

To clarify, if you call out (LAN -> WAM) the entire conversation works and you get audio in both directions and the connection is stable? It's purely a matter of incoming calls not working?

Any other details? Are you using SDWAN, etc? (I'm just naming something that changed in the new release, probably not an issue with you.)

Hello Shawn Adams,

Thank you for reaching out to community, could you please refer the article below  and refer the changes: 

UDP timeout: https://docs.sophos.com/nsg/sophos-firewall/19.0/Help/en-us/webhelp/onlinehelp/AdministratorHelp/RulesAndPolicies/FirewallRules/VoIPDropUDPTimeout/index.html#

IPS: https://docs.sophos.com/nsg/sophos-firewall/19.0/Help/en-us/webhelp/onlinehelp/AdministratorHelp/RulesAndPolicies/FirewallRules/VoIPDropVPN/index.html

Also check which module is loaded currently with the command line: console> system system_modules show
https://docs.sophos.com/nsg/sophos-firewall/19.0/Help/en-us/webhelp/onlinehelp/AdministratorHelp/RulesAndPolicies/FirewallRules/FirewallVoIP/index.html

here you can try loading and unloading the system modules...
https://docs.sophos.com/nsg/sophos-firewall/19.0/Help/en-us/webhelp/onlinehelp/AdministratorHelp/RulesAndPolicies/FirewallRules/VoIPSIPModuleTurnOnOff/index.html

Hello Vivek,

Thank you for the links but I think you misunderstand the issue,  it isn't the call that's the issue.  Its is that the software can not connect to the Telecommunications Server.  As I said above the server is pingable but the software can no longer find it.  It worked perfectly fine before the update. After the update it no longer works at all.

Hey Shawn Adams, 

So if I understood correct, the traffic is WAN to LAN, so there must be DNAT [screenshot of the NAT rule] rule in place right?
Can you share the screenshot and diagnostic packet capture when someone tries to access the application from WAN to LAN?
Monitor traffic using Packet Capture Utility : https://support.sophos.com/support/s/article/KB-000035761?language=en_US

Hi Vivek,

After working on this until Midnight last night I found the reason it stopped working.  In the Default SNAT IPv4 the VoIP VLAN outbound interface was missing. I re-added it and it started working right away.  Why it was missing after the update to 19 is a question I have for another day.  Right now I'm happy its working. Thank you for your help.  The links you provided were very useful in checking that everything was set up correctly on my end.