Small group multicast in a computer network
US7016351B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 29, 2000 |
| Grant date | Mar 21, 2006 |
| Priority date | — |
| Expiry date | Feb 29, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L45/26
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The invention solves the problem of overloading intermediate routers with state information as the number of multicast groups increases to millions of groups. The invention places multicast delivery tree information in the header of an encapsulated multicast packet, thereby relieving the routers from maintaining any state information about the multicast groups. The encapsulated packet is referred to as a small group multicast packet, or SGM packet. Routers which are neither branch points of the delivery tree nor destination routers will also need to do no additional forwarding processing other than that needed for standard unicast forwarding. A protocol designation field in the Layer 3 header informs the router that the packet is a SGM packet, and that the router is therefore instructed to parse the packet for route information. The router parses the SGM packet header and determines the next hop address of routers in the multicast delivery tree. The standard unicast forwarding tables are then consulted to determine the next packet destination addresses, and the router then rewrites the SGM packet and routes it to the next hop router. The routing tables also instruct the router as t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.