EFFICIENT MULTICAST MAPPING IN A NETWORK SWITCH

摘要

An apparatus and technique for mapping of a multicast identifier MID to a local identifier CID is disclosed. Table entries for such mapping can be disposed in non-contiguous memory locations. A pointer is employed in each entry to indicate the location of any subsequent memory location associated with the MID. CIDs and associate memory locations are allocated only for ports that participate in a connection. Based upon the MID, a first table (T1) provides an index into a second table (T2) which includes entries having a port identification field (20), pointer field (22) and a CID field (24). The CID field indicates the CID associated with the port indicated by the port identification field (20). The pointer indicates further entries in the second table that are associated with other copies of the cell to be transmitted in the multicast connection. The CID is employed to obtain a VPI and a VCI from a third table (TT).