What's meant by multipoint circuits? Can you give me examples? I already know the configuration of a Frame Relay multipoint design, for example. But I still feel uncomfortable defining the concept of multipoint.
with multipoint the meaning is that from a single DTE you are able to reach multiple remote DTE through the WAN cloud.
Actually, in a FR cloud you can configure a point-to-multipoint subinterface.
Here the multipoint capabilities is achieved by using multiple point-to-point logical PVCs that connect the local DTE router to all the remote devices.
Multicast and broadcast is not supported natively by the FR cloud and so multicast and broadcast traffic has to be replicated over each PVC / every DLCI.
This is the meaning of the broadcast option that can be added in the frame-relay map ip command
frame-rel map ip 10.10.10.2 150 broadcast
10.10.10.2 is the remote DTE ip address
150 is the local DLCI to be used to put the frame on the PVC to the remote DTE.
In ATM NBMA multipoint circuits are supported also without using multiple p-t-p PVCs
A point-to-multipoint ATM connection connects a single source end-system (known as the Root node) to multiple destination end-systems (known as leaves). Such connections are unidirectional only. Root nodes can transmit to leaves, but leaves cannot transmit to the root or to each other on the same connection.
Hope to help