ATM Point to Multipoint

ATM falls into the category of rooted data and rooted control planes. An application acting as the root would create c_root sockets and counterparts running on leaf nodes would utilize c_leaf sockets. The root application uses WSAJoinLeaf to add new leaf nodes. The corresponding applications on the leaf nodes will have set their c_leaf sockets into listen mode. WSAJoinLeaf with a c_root socket specified is mapped to the Q.2931 ADDPARTY message. The leaf-initiated join is not supported in ATM UNI 3.1, but is supported in ATM UNI 4.0. Thus WSAJoinLeaf with a c_leaf socket specified is mapped to the appropriate ATM UNI 4.0 message.

There are additional considerations to bear in mind for ATM point-to-multipoint:

• The addition of new leaves to the ATM point-to-multipoint session is invitation-based only. The root invites leaves — which have already their accept function call — by calling the WSAJoinLeaf function.
• The flow of data in an ATM point-to-multipoint session is from root-to-leaves only; leaves cannot use the same session to send information to the root.
• Only one leaf per ATM adapter is allowed.