Multicast system for forwarding desired multicast packets in a computer network
US6847638B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 2000 |
| Grant date | Jan 25, 2005 |
| Priority date | — |
| Expiry date | Jan 4, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/185
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for a router to inform a Layer 2 switch by use of packets of a new router group port management protocol (RGMP) that the layer 2 switch is to forward multicast packets of a specified group to the router. First the router transmits a RGMP HELLO packet to the layer 2 switch to inform the switch that the router is a multicast router implementing the invention. Then, in the event that the router receives an IGMP packet from an end station requesting multicast packets of a particular group, in response the router sends an RGMP JOIN packet to the layer 2 switch. The RGMP JOIN packet requests that the layer 2 switch forward only multicast group packets, of the group whose group number is written into a field of the RGMP JOIN packet, to the router. Also, the router sends a prior art PIM JOIN packet to other multicast routers in order to be placed on the multicast distribution tree for that group. The layer 2 switch builds a forwarding table for multicast groups listing ports connected to routers having sent a RGMP JOIN for that group. When a multicast group packet arrives at the layer 2 switch, the switch uses the forwarding table to forward the packet only to those …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.