Ishan S Wu

7385977, Jun 10, 2008

Sep 10, 2004

10/939100

Ishan Wu - Cupertino CA, US
Nagarani Chandika - Sunnyvale CA, US
Yiqun Cai - Cupertino CA, US

Cisco Technology, Inc. - San Jose CA

H04L 12/28

370389, 370469

A method and apparatus for a downstream router to inform an upstream router by use of packets of a new router command protocol that the upstream router is to forward multicast packets of a specified group to the downstream router. First the downstream router transmits a HELLO packet to upstream router to inform the upstream router that the downstream router is a multicast router implementing the invention. Then, in the event that the downstream router receives a packet from an end station requesting multicast packets of a particular group, in response the downstream router sends a JOIN packet to the upstream router. The JOIN packet requests that the upstream router forward the requested group multicast packets to the downstream router. When a multicast group packet arrives at the upstream router, the upstream router forwards the packet to those downstream routers requesting that group.

8040884, Oct 18, 2011

Aug 8, 2005

11/198999

Senthil Arunachalam - Fremont CA, US
Sundher Narayanaswamy - San Jose CA, US
Isidoros Kouvelas - Redwood City CA, US
Ishan Wu - Cupertino CA, US
Toerless Eckert - Mountain View CA, US

Cisco Technology, Inc. - San Jose CA

H04L 12/54

370390

A method, system, computer program product and apparatus are presented to enable a L2 network device, such as a bridge or switch, to control the flow of a multicast data stream to a connected router in response to control messages received from the router by the L2 network device. By controlling the flow of multicast data streams in this manner, there will be a corresponding reduction in wasted bandwidth due to unnecessary transmission of these multicast data streams and a reduction in processing overhead by the router due to analysis and dropping of unnecessary multicast frames. In one aspect of the present invention, the router can generate the control messages in response to receiving a data frame in a multicast data stream from the L2 network device. The router can determine whether a subscriber to that multicast data stream is connected downstream of the router and then transmit an appropriate control message to the upstream L2 network device, indicating whether the router does or does not have a downstream subscriber. In response to such a control message, the L2 network device can cease transmitting the multicast data stream to the router, if appropriate.

6847638, Jan 25, 2005

Oct 16, 2000

09/688895

Ishan Wu - Santa Clara CA, US
Nagarani Chandika - Santa Clara CA, US
Yiqun Cai - Santa Clara CA, US

Cisco Technology, Inc. - San Jose CA

H04L 1256

370389

A method and apparatus for a router to inform a Layer switch by use of packets of a new router group port management protocol (RGMP) that the layer switch is to forward multicast packets of a specified group to the router. First the router transmits a RGMP HELLO packet to the layer 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 switch. The RGMP JOIN packet requests that the layer 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 switch builds a forwarding table for multicast groups listing ports connected to routers having sent a RGMP JOIN for that group.