Understanding Frame-Relay Subnet Requirements

To start know that frame-relay can be configured with one subnet between all routers in the frame relay cloud or one subnet per PVC (Private Virtual Circuit). We will now cover when a single subnet is used vs multiple subnets.

Full Mesh Network


When the frame relay network is configured in a full mesh, meaning every router is connected to every other router in the network much like a LAN, frame relay is configured with a single subnet. For example if the subnet 192.168.1.0/24 was used, R1 could be 192.168.1.1, R2 192.168.1.2, and R3 192.168.1.3 and so on. 

Partial Mesh Network


Much like a hub and spoke network a partial network must use different subnets between each pair of routers for frame relay. Example would be the network between R1 & R2 configured with network 
192.168.1.0/24 and R1 to R3 configured with 192.168.2.0/24.