Multicast packet duplication at random node or at egress port with frame synchronization
US6751219B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 2000 |
| Grant date | Jun 15, 2004 |
| Priority date | — |
| Expiry date | Apr 20, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q2011/0047
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Multicast is performed in a packet-based network switch having a switch fabric of store-and-forward switch nodes. Congestion and blocking at an ingress port is avoided because packet replication is performed at random nodes dispersed throughout the switch fabric. Each multicast packet inserted into the switch fabric by the ingress port is sent to a randomly-selected node. The random node replicates the multicast packet into many unicast packets that are routed to egress ports. A SONET frame can be divided into several multicast packets that are dispersed to different random nodes before replication, thus dispersing congestion. Replication can be delayed until the next SONET frame to prevent latency build up from propagation delays in the switch fabric. Alternately, the SONET payload envelope pointer can be advanced by the propagation delay. Lookup tables at the random nodes can include a list of destinations so that all the destination addresses do not have to be stored in each multicast packet header.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.