Talk about a terrible ISP! Here is a trace of SBHTTP showing downtime experienced by Sprint Broadband users in Tucson, Arizona. Talking to the Sprint Broadband technical support, they don't know 1) what's causing the problem or 2) when (if?) it will be fixed. Last time I talked to them they said the Tucson has been experiencing these intermittent outages for about to two months.
On a positive note, you can see how SBHttp can be used to evaluate the performance of an Internet Service Provider. The throughput graph shows how fast the connection is (in Bytes/Second), and the latency graph shows how long it takes to start retrieving a request. Periods where the Internet service is down is shown as a 0 in both throughput and latency. The little red circles were drawn by me to illustrate the points on the graph.