Silent Audio Calls

I don’t understand why you think the XG is blocking internal traffic within your network, that traffic should be routed by your switches?
ian

I was using a Cyberoam previously, after migrating to the XG firewall all calls went silent. I then rolled back to Cyberoam and calls are working again. This is why I'm pointing fingers to the firewall.

Just to give more insight , the firewall is the gateway for my vlans ,where inter-vlan routing is enabled. The phones and the pbx server are on differents vlans so when initiating calls traffic has to cross the firewall. its my understanding that RTP flows between the phones directly but somehow it appears they go through the firewall in my environment.

Thank you for the update. Do you have a firewall rule allowing all traffic in both directions across the vlans?

ian

yes its the first rule it allows any to any traffic with any service enabled 

Which version of XG are you using? If v18 try disabling ssl/tls as a test?
ian

yes its version 18 , I'll be sure to try this.

The online help has some help for this use case: https://docs.sophos.com/nsg/sophos-firewall/18.0/Help/en-us/webhelp/onlinehelp/nsg/sfos/troubleshooting/VoIPDropUDPTimeout.html?hl=voip

thanks Luca , I had already tried this but the issue still persisted , I'm losing hope 

Hello David,

Thank you for contacting the Sophos Community.

Adding to what Rfcat and Luca have mentioned, also check for entries on DoS.

Go to Intrusion Prevention >> DoS & Spoof protection >> if it’s enabled try disabling.

If the issue remain SSH to XG (5>4)  and you’ll end in the console:

console> drop-packet-capture 'host x.x.x.x' (Where x.x.x.x is the IP of one of the phones) Check if you find any drop packets for VoIP connections. 

Regards,