Hierarchical routing knowledge for multicast packet routing
US6611528B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 2000 |
| Grant date | Aug 26, 2003 |
| Priority date | — |
| Expiry date | Oct 10, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L45/16
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The invention provides a method and system for multicast packet routing, in which only selected routers in a network subset (in a preferred embodiment, those routers on the border of the domain) maintain routing information external to the network subset, while all other routers in the network subset (non-border routers) maintain only information regarding routing within the network subset, including which border routers are on the path from the multicast source device or to the destination devices. The network subset is preferably a domain or other routing domain. A multicast distribution tree is maintained, using protocol messages which are transmitted from leaf nodes toward a root of the tree, while data packets to be multicast are distributed from the root toward the leaf nodes. In each network subset, such as a routing domain, each multicast packet is associated with a multicast distribution tree. The multicast distribution tree is associated with an upstream border router (UBR) and a set of downstream border routers (DBRs). The UBR and DBRs maintain complete routing information for each multicast source device, while all other routers in the network subset maintain routing in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.