Our ISP has set up a Cisco 2431-16fxs IAD (dual WAN) in one of our locations. It is used to connect the devices (PCs and SIP phones) on our LAN to internet (via 1st WAN port) and ISP's MPLS-based voip network (via 2nd WAN port).
We have 2 LAN subnets - the first subnet (PCs) requires internet access only, so it goes out via the 1st WAN port. The 2nd subnet (SIP phones) is connected the MPLS network (via 2nd WAN port).
We would like to have the SIP phones (that connects to MPLS-based network 192.168.1.x) to be able to access the internet. Is it possible to configure the IAD so that the phones are routed based on destination network; i.e. anything to 192.168.1.x via 2nd WAN port, anything else to the internet via the 1st WAN port?
Our ISP first said this is possible, now they are saying we need a firewall to do this. I'm not a network engineer - I just wanted to confirm if this is the case.
Thanks,
Matt
