I've been pinging each of the 1022 hosts in 65.174.248.0/22 since the afternoon session on monday. The primary goal is to discover how many people are using DHCP vs Static, and Wired vs Wireless. Its likely that some people have configured their laptops to deny incoming ICMP, so they won't be counted.

Fig 1: The red dots represent individual ICMP replies. The green line is the median RTT over a 10-minute sliding window. You can see how wireless performance improved around 15:30 Monday when we disabled 2Mb/s support on the WAPs.

Fig 2: Each point on the plot is an ICMP echo reply. The different colors show which pool a host's address belongs to.

Fig 3: This figure also has one point for each ICMP echo reply. It shows when hosts come and go. The always-on hosts in the DHCP pool are probably the 15 or so boxes in the terminal room. This data probably shows that some of these hosts received addresses from one of the other DHCP servers (Eliot's box or Cisco's router).

Fig 4: This plot shows how many hosts are alive on the network within 20-minute sliding window.

Fig 5: Histogram of Mean RTTs during the Tuesday morning session. Assuming all wired hosts are < 2ms, and wireless are > 2ms, I count 46 wired hosts and 340 wireless hosts. This count excludes the ``infrastructure'' hosts (although Fig 4 does not).