Switching IP over ATM
- OSPF is used as IGP (Interior Gateway Protocol), which enables the routers to share the information about link costs and outages.
- Unless there is an outage lowest cost PVC joining any two routers is used.
- Incase of outage a backup PVC is used if available.
- Otherwise alternate route is choosen using the information provided by OSPF. At IP layer this route will appear as 2 or more hops long.