Method and apparatus for wire speed IP multicast forwarding
US6754211B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 1, 1999 |
| Grant date | Jun 22, 2004 |
| Priority date | — |
| Expiry date | Dec 1, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L69/22
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a switch including a plurality of ports, an IP Multicast packet arriving on an ingress port a copy of the receiver packet is forwarded to each member of the IP Multicast group at wire-speed. The packet is bridged once to a given egress port and may be routed multiple times out of the egress port. If multiple subnets exist on an egress port, each subnet that requires a copy of the packet will receive the packet with its VLAN ID included in the packet. The received IP Multicast packet for an IP Multicast group is stored in memory, a pointer to the location of the packet in memory is stored for each port to which a copy of the packet is to be forwarded. An IP Multicast forwarding entry is provided for the IP Multicast group. The forwarding entry includes a modification entry for each packet to be forwarded to the IP Multicast group. A copy of the stored packet is modified dependent on the modification entry and forwarded in the next available port cycle for the port.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.