Patent ID: 8363649
Filing Date: 2013-01-29
Classification: H04L

Abstract:
1. A network having a plurality of multicast connections, said network comprising: N when N  where N>1, d an input stage comprising  input switches, and said each input switch comprising d inlet links and each said input switch further comprising x×d outgoing links connecting to switches in a second stage where x>0; and an output stage comprising  output switches, and said each output switch comprising d  incoming links connecting from switches in a penultimate stage; and a plurality of y middle stages comprising N/d middle switches in each of said y middle stages wherein said second stage and said penultimate stage are one of said middle stages where y>3, and said each middle switch in all said middle stages excepting said penultimate stage comprising x×d incoming links (hereinafter “incoming middle links”) connecting from switches in its immediate preceding stage, and said each middle switch further comprising x×d outgoing links (hereinafter “outgoing middle links”) connecting to switches in its immediate succeeding stage; and said each middle switch in said penultimate stage comprising x×d incoming links connecting from switches in its said immediate preceding stage, and said each middle switch further comprising  outgoing links connecting to switches in its said immediate succeeding stage i.e., said output stage; or when N  and an input stage comprising  input switches, and said each input switch comprising d  outgoing links connecting to switches in a second stage where x>0; and an output stage comprising  output switches, and said each output switch comprising d outlet links and said each output switch further comprising x×d incoming links connecting from switches in a penultimate stage; and a plurality of y middle stages comprising N/d middle switches in each of said y middle stages wherein said second stage and said penultimate stage are one of said middle stages where y>3, and said each middle switch in said second stage comprising  incoming links connecting from switches in its immediate preceding stage i.e., said input stage, and said each middle switch further comprising x×d outgoing links connecting to switches in its immediate succeeding stage; and said each middle switch in all said middle stages excepting said second stage comprising x×d incoming links (hereinafter “incoming middle links”) connecting from switches in its immediate preceding stage, and said each middle switch further comprising x×d outgoing links (hereinafter “outgoing middle links”) connecting to switches in its said immediate succeeding stage; and wherein said each multicast connection from an inlet link passes through at most two outgoing links in said input switch, and said multicast connection further passes through a plurality of outgoing links in a plurality switches in each said middle stage and in said output stage.