ASAs are not allowed to establish an IPSEC tunnel and a Cisco EASY VPN tunnel on the same device. This is a device limitation from Cisco. While it is possible to have multiple IPSEC tunnels on this device. It is not possible configure an Easy VPN tunnel for voice as well as an IPSEC tunnel for data. The ASA for the phones can only be used to connect to CallTower.
*** Note – Cisco Easy VPN is required to connect back to the hosted network. IPSEC is not available or supported