VPN connectivity to AirVantage FOTA server


We are attempting to keep our VPN as secure as possible but would like to consider the Sierra FOTA functionality for our systems in the field under AT&T’s M2M network. Sierra suggests that we only need to allow outgoing traffic from the devices in order to get the FOTA functionality working, however we would like to restrict that outgoing traffic just to the necessary Sierra server(s) for FOTA to work.

Does Sierra list the appropriate IP Address(es) necessary to allow outgoing traffic to for AirVantage FOTA to work?