Echo Problem with VOIP Device

First things first. I am a total noob with XG Firewall. I have been running Untangle on my home network and wanted to take a look at Sophos as I hear it might be a better way to go. I have installed SFVH (SFOS 17.1.3 MR-3) in the past few days and am beginning to find my way around.

So far my biggest problem is with my OOMA VOIP device. When talking on the phone I hear an echo of my voice. This did not happen with my Untangle setup as they had a builtin for SIP/VOIP. What is required to remove the echo when using XG Firewall?

Thanks,

callen godfrey