Non Broadcast Multi-Access (NBMA) clouds such as Frame Relay or X.25, are always a challenge. The combination of low bandwidth and too many link-states is a recipe for problems. A partial mesh topology has proven to behave much better than a full mes...
http://www.ebrahma.com/2013/10/non-broadcast-mode-example-full-mesh/Labels: Characteristics, configuration-in-non-broadcast, DR-/BDR, NBMA, Non-Broadcast-Mode, Non-Broadcast-Multi-Access, OSPF, OSPF-neighbor, Partial-Mesh, point-to-multipoint, RFC-compliantnon-broadcast