XG / VOIP - anything to know

Question

Hey all, 
 
 I am about to inherit a Hosted VOIP phone system and will be running it though an XG Firewall. 
 
 I have disabled ALG but other than QOS are there any other considerations I will need to consider? 
 Probably a Firewall rule to allow traffic to the VOIP Ports so I wont need to make a Ussr for them all. 
 
 Open to any advice. 
 
 Cheers

LuCar Toni · Accepted Answer

You should take a quick look, what your VoIP System is actually doing and how it works. 
 https://community.sophos.com/kb/en-us/127785 
 
 Basically XG can pick up the connection via SIP and open the ports, considered as Traffic Ports. 
 https://en.wikipedia.org/wiki/Session_Initiation_Protocol 
 
 Another point is, there is something like UDP Timeout on XG (like all other Stateful Firewalls). 
 Maybe you have to increase this Timeout to avoid dropping connections.

VishvasChitale · Answer

Hi 
 I am running VOIP SIP switch in VM and SOPHOS XG as VM for last of couple of years. Only issue is don't open SIP switch through firewall rule, 
 it gets hacked. I have kept SIP Switch inside only and use VPN for Access for mobile users and RED for branch office . Try to use codec G729 which is advance low bit rate. 
 I am using Bria application for Mobiles and PC as SIP client 
 Best Regards 
 Vishvas