I am trying to build a WAN connecting various LAN's via frame-relay for learning purposes, i do not have that much experience with frame-relay or network design (mainly creating LAN's and connecting them through frame-relay).
This is the topology here, there are two sub interfaces on serial ports to avoid split horizon and connect to both other routers. The part I'm getting stuck on, is if my understanding is correct and i should have an edge router that connects to the ISP giving connectivity to the internet throughout the WAN or does every router connect to an ISP for connectivity on the LAN, i will be using a loopback address to simulate the ISP here: