Stream Blocking Probability (SBP)
One of the key metrics obtained from the media grid and ISTP clients, stream blocking probability is analogous to call blocking probability in the world of telephony. It refers to the likelihood that a given ISTP stream may not receive service through a sequence of unmediated Internet bottlenecks on its way to the destination or not be admitted via the media grid due to lack of mediated capacity. ISPs who consistently have high stream blocking probability above the maximum threshold set by the Association, may not receive settlement for their premium bandwidth services and may lose status as an association provider along with their privilege of using the InterStreamSM service mark. The InterStream Oversight Board will set the minimum SPB requirements.
In essence, the SBP represents an "Erlang formula" for the broadband Internet. Unmediated broadband bottleneck's SBP can be ascertained empirically and derived via the Association's use of a designated TCP. Media Grid Engines will self-tune themselves to ensure minimum SPB standards are maintained for both InterStream and non-InterStream providers. Mediated bottlenecks may have statistically predictable SBPs. Ultimately, as media grid engines gain forwarding ability, in addition to the proxy capability during the pilot, the association expects full linear predictability for video streaming can be obtained. A "true Erlang-style model" for both the backbone of the Internet as well as the broadband networks will emerge.