Why would you use PPOE if you already have a router? The E-Smith machine should be configured to accept an IP Address similar to the one handed out by the westel router. Configure E-Smith's default gateway to be the IP Address of your westel router.
Lets assume the following:
Westel Router: 192.168.1.1/255.255.255.0
E-Smith machine should be configured:
IP Address: 192.168.1.2
Subnet: 255.255.255.0
Default Gateway: 192.168.1.1
Hope this helped,
Nathan