  Optimal dissemination schemes have previously been studied for peer-to-peer
live streaming applications. Live streaming being a delay-sensitive
application, fine tuning of dissemination parameters is crucial. In this
report, we investigate optimal sizing of chunks, the units of data exchange,
and probe sets, the number peers a given node probes before transmitting
chunks. Chunk size can have significant impact on diffusion rate (chunk miss
ratio), diffusion delay, and overhead. The size of the probe set can also
affect these metrics, primarily through the choices available for chunk
dissemination. We perform extensive simulations on the so-called random-peer,
latest-useful dissemination scheme. Our results show that size does matter,
with the optimal size being not too small in both cases.
