Sophos XG VoIP Problem

Hello there,

Thanks for reaching out to Sophos Community 

Could you access Sophos Firewall Device Console and check if H.323 loader is loaded?

type in this command in console to check:  system system_modules show

If the H.323 helper module is loaded along with proper firewall rules or DNAT rules, and audio or video continues to drop or only works one way, application-level NAT might not be occurring

Kindly follow this doc guide on the steps for troubleshooting: https://docs.sophos.com/nsg/sophos-firewall/19.5/Help/en-us/webhelp/onlinehelp/AdministratorHelp/RulesAndPolicies/FirewallRules/VoIPH323CallIssues/index.html

Kindly let us know how it goes. Many thanks for your time and patience and thank you for choosing Sophos

Cheers,

Thanks for the reply.

We tried the folllowing things without success:

Unload the H.323 Helper module

Unload the SIP module

Unload both

Raised the UDP Timeout Stream to 150 and 300

Raised the UDP Timeout to 150 and 300

Do we need to restart something after we unload the modules or should it just work?

Hi Pascal,

Thank you for reaching out to Sophos Community.

Kindly try to Power off the VoIP phone and turn it on again after 60 seconds

Also, Kindly share your network setup of VoIP and firewall and compare the working and nonworking tcpdump,drppackt and conntrack -E

Hi,

we solved our problem.

Our telephone devices are connected behind REDs and our VoIP Clients are in the same network as the SBC. After viewing the packets with tcpdump I saw that the incoming traffic was not showing on the RED network.

After that I checked the routes in our SBC for the RED network and discovered an error in the config. After fixing this everything worked like a charm.

Thank you for the tip to scan the packets with tcpdump.  

Hi Pascal,

That is great to hear.