I think you are missing some basics concepts of networking. Your description above shows two NIC’s on the same subnet. That will confuse Linux as it is not sure which NIC to use for incoming/outgoing traffic.
Carefully review section 2.4 of the HAAst installation guide before going any further. If you are new to networking/multihoming/routing then you will find all HA product difficult to install or get working properly.
If this is for a commercial environment I would recommend you engage Telium professional services to perform the installation for you (or at least the network/VoIP NIC portion). If you wish, our engineers can also walk you through the key concepts of networking and multihoming, to help you understand what they configured and why.