System for delay optimization for scheduling in bufferless crossbar switches

Abstract

A system for delay optimization scheduling in bufferless crossbar switches includes a plurality of line cards, each line card having an ingress half, an egress half, and a partial scheduler, wherein each line card is configured to transmit scheduling information to a horizontal control broadcast network and a vertical control broadcast network; a plurality of couplers connected by control links to the line cards in a two-dimensional grid, organizing the line cards into rows and columns; a bufferless crossbar switch connected by data path links to each line card to the ingress half and the egress half; wherein control information is distributed in a first stage and a second stage of broadcasts.

1 . A system for delay optimization scheduling in bufferless crossbar switches, comprising: 
 a plurality of line cards, each line card having an ingress half, an egress half, and a partial scheduler, wherein each line card is configured to transmit scheduling information to a horizontal control broadcast network and a vertical control broadcast network;    a plurality of couplers connected by control links to the line cards in a two-dimensional grid, organizing the line cards into rows and columns;    a bufferless crossbar switch connected by data path links to each line card to the ingress half and the egress half;    wherein control information is distributed in a first stage and a second stage of broadcasts.    
   
   
       2 . The system of  claim 1 , wherein the bufferless crossbar switch is a replicated distributed responseless crossbar switch.  
   
   
       3 . The system of  claim 1 , wherein each coupler operates as a control broadcast network in either a horizontal or a vertical direction.  
   
   
       4 . The system of  claim 1 , wherein control information is distributed across the rows in the first stage and across the columns in the second stage, so that each line card receives redundant control information from all the other line cards.  
   
   
       5 . The system of  claim 1 , wherein a minimum delay topology is determined based on one or more of: a number of nodes, a delay overhead for initiating a message, and a delay per node hop delay.  
   
   
       6 . The system of  claim 1 , wherein the two-dimensional grid is logically partitioned into a plurality of partitions by using a mask in a control plane to limit a range of addressable ports.  
   
   
       7 . The system of  claim 6 , wherein different levels of quality of service are provided in different partitions.  
   
   
       8 . The system of  claim 6 , wherein inter-switch traffic and switch-to-node traffic are partitioned into different partitions.  
   
   
       9 . The system of  claim 6 , wherein the partitions are re-configurable in response to changing traffic conditions.  
   
   
       10 . The system of  claim 6 , wherein at least one partition is configured as a backup.  
   
   
       11 . The system of  claim 1 , wherein each line card transmits the scheduling information approximately simultaneously to the horizontal and the vertical control broadcast networks connected to that line card.