N inputs OUTPUT BUFFER

• Scheduling: choose a packet to transmit over a link among all packets stored in a given buffer (multiplexing point) • Mainly look at QoS scheduling algorithms – Choose the packet according to QoS needs Computer Network Design- 3 Andrea Bianco – TNG group- Politecnico di Torino Output buffered architecture • Advantage of OQ (Output Queued) architectures – All data immediately transferred to output buffers according to data destination – It is possible to run QoS scheduling algorithms independently for each output link • In other architectures, like IQ or CIOQ switches, problems become more complex – Scheduling to satisfy QoS requirements and scheduling to maximize the transfer data from inputs to outputs have conflicting requirement