Multicasting

There are two types of session establishment: rooted and nonrooted. In rooted he c_root must remain present for the whole duration of the multipoint session, as the session is broken up in the absence of the c_root. The c_root usually initiates the multipoint session by setting up the connection to a c_leaf, or a number of c_leafs. The c_root may add more c_leafs, or (in some cases) a c_leaf can join the c_root at a later time. There are two types of data transfer styles: rooted and nonrooted. Data transfer only occurs between the d_root and the rest of the members of this multipoint session, each of which is referred to as a d_leaf. The traffic could be unidirectional or bi-directional. The data sent out from the d_root is duplicated (if required) and delivered to every d_leaf, while the data from d_leafs only goes to the d_root.