Topics * Router design * Wireless ** MAC ** High Capacity wireless ** Routing ** Wireless diversity ** Sensor networks * Overlays ** RON ** Gnutella/ GIA * DHTs (Chord) * Applications of DHTs (DOA, i3) * Multicast * Security ** DDoS ** Worms * Router design ** Crossbar ** Scheduling (bipartite matching - input -> output) *** PIM **** Input ports send requests to output ports **** Grant phase: output ports accept inputs **** Repeated until all inputs are matched *** iSLIP **** Round-robin (vs random) grant phase * Wireless ** WIreless MAC *** Exposed & hidden terminal problems *** 802.11 - backoff time randomly chosen from [0, CW]; ACK *** Reservation -- RTS/CTS = MACA **** MACAW: adds other stuff *** TDMA: fixed time slots ** High Capacity *** MAC: fewer collisions *** Error control *** Spatial reuse **** 1/log n falloff of SNR **** 1/sqrt(n) per-node network capacity ** Routing *** DSDV - destination sequence distance vector *** DSR - source routing *** AODV - *** ETX metric **** ETX = 1/ (df * dr) **** df = probability packet arrives at destination, dr = prob ack arrives ** Wireless diversity *** ExOR *** MRD ** Sensornets