The thunder of distant Net storms

Abstract

Computers and routers on the Internet send each other error messages (called ICMP datagrams) to signal conditions such as network congestion or blackouts. While these datagrams are very rare, less than 0.001% of total traffic, they hold very important global information about problems and congestions elsewhere in the Net. A measurement of the flow of such error messages in our local cluster shows a very pathological distribution of inter-message times: $P(\Delta t) \approx 1/\Delta t$. This scaling extends for about seven decades, and is only punctuated by extraneously periodic signals from automatons. More than a half of these error messages were themselves generated erroneously.