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:
May. 06, 2003
Filed:
Jul. 15, 1999
James Scott Hiscock, Rockport, MA (US);
Benny Siman-Tov, Framingham, MA (US);
Terrence Hussey, Merrimack, NH (US);
3Com Corporation, Santa Clara, CA (US);
Abstract
Packets received by a network device such as a switch are queued to either a multicast or unicast queue depending on whether a valid mapping of the packet destination address to an output port of the device exists. Each queued packet is marked with a service era during which the message is queued. The service era is advanced whenever a port mapping for a destination address becomes established and the multicast queue is non-empty. The device monitors the presence of packets on the multicast queue and the transfer of packets from the multicast queue to the output ports. A message is forwarded from the unicast queue to an output port only if the multicast queue was empty at the time the mapping was established, or if all messages on the multicast queue from service eras earlier than the service era of the message on the unicast queue have been transferred to the output port. The multicast queue is monitored via a synchronization flag variable that is updated whenever a packet is forwarded from the multicast queue. A packet is forwarded from the unicast queue only if it is marked with an era no later than the value of the synchronization flag.