The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 25, 2005
Filed:
Oct. 16, 2000
Ishan Wu, Santa Clara, CA (US);
Nagarani Chandika, Santa Clara, CA (US);
Ramana Mellacheruva, Santa Clara, CA (US);
Yiqun Cai, Santa Clara, CA (US);
Ishan Wu, Santa Clara, CA (US);
Nagarani Chandika, Santa Clara, CA (US);
Ramana Mellacheruva, Santa Clara, CA (US);
Yiqun Cai, Santa Clara, CA (US);
Cisco Technology, Inc., San Jose, CA (US);
Abstract
A method and apparatus for a router to inform a Layerswitch by use of packets of a new router group port management protocol (RGMP) that the layerswitch is to forward multicast packets of a specified group to the router. First the router transmits a RGMP HELLO packet to the layerswitch 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 layerswitch. The RGMP JOIN packet requests that the layerswitch 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 layerswitch 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 layerswitch, the switch uses the forwarding table to forward the packet only to those routers requesting that group.