Patent ID: 6658016
Filing Date: 2003-12-02
Classification: H04L

Abstract:
A packet switching fabric comprising:means forming a data ring, means forming a control ring, and means forming a plurality of data communication network links each having at least one network node coupled thereto; and a plurality of output queuing controlled switching devices coupled together by said data ring means and said control ring means so that said network links can be selectively communicatively coupled, each said switching device including, data ring processing means for transmitting and receiving bursts of data to and from adjacent ones of said devices via said data ring means, network interface means having at least one network port for transmitting and receiving data packets to and from said network links, packet buffer means for storing the received data packets, source managing means communicatively coupled to said data ring processing means, and providing an interface between said network interface means and said packet buffer means, said source managing means being operative to develop pointer information for storing and reading each one of said received data packets to and from said packet buffer means, and also being operative to develop destination identification information associated with each one of said received data packets, said destination identification information indicating an associated destination one of said network ports of an associated destination one of said devices, said received data packets including transfer packets received at an associated source one of said devices that is different from said associated destination device, and local packets for which said associated destination network port is a port of said associated source device, the pointer information and destination identification information associated with each one of said local packets providing local announcement information serving as a local request for access to said associated destination network port, the pointer information and destination identification information associated with each one of said transfer packets providing transfer announcement information, control ring processing means responsive to said transfer announcement information, and operative to transmit and receive control messages to and from adjacent ones of said devices via said control ring means, said control messages including announcement messages each being associated with one of said transfer packets and carrying said associated transfer announcement information, said control ring processing means also being operative to provide received transfer announcement information in response to each received one of said announcement messages, said received transfer announcement information serving as a remote request for access to said associated destination network port, destination managing means communicatively coupled to said network interface means, and responsive to said local announcement information and said received transfer announcement information, and operative to arbitrate between competing ones of said local and remote requests for access to each of said network ports, and also operative to generate transfer notification information associated with selected ones of said transfer data packets; said control messages further including transfer notification messages developed by said control ring processing means in response to said transfer notification information, each said notification message being associated with one of said transfer data packets and carrying source identification information indicative of said associated source device, each said notification message indicating to said associated source device that said associated selected transfer data packet has been granted access to said associated destination network port.