Efficient multicast mapping in a network switch
US5903564A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 1997 |
| Grant date | May 11, 1999 |
| Priority date | — |
| Expiry date | Aug 28, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2012/5681
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An apparatus and technique for facilitating mapping of a Multicast Circuit Identifier ("MID") to a Local Circuit Identifiers ("CID") is disclosed. Table entries for such mapping can be disposed in non-contiguous memory locations. A pointer is employed in ca h entry to indicate the location of any subsequent memory location associated with the MID. CIDs and associated memory locations are allocated only for ports that participate in a connection. To implement the apparatus and technique a first table provides an index into a second table based upon the MID. The second table includes entries having a port identification field, a pointer field and a CID field. The CID field indicates the CID associated with the port indicated by the port identification field. The CID is written to the header of the copy of the cell to be transmitted to the indicated port. 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, if such entries exist. The CID is employed to obtain a Virtual Path Identifier ("VPI") and Virtual Circuit Identifier ("VCI") from a third table.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.