p2psp team mailing list archive

[Vicente Gonzalez <vicente.gonzalez.ruiz@xxxxxxxxx>]

Hello,

one of key indicators that can be measured in a cluster P2PSP is the amount
of data that travels through it. In this post I show a simple way to
calculate this amount when the entire cluster runs on a single host, which
happens when we are doing, for example, a simulation.

1. We look at the number of bytes sent and received:

/sbin /ifconfig lo

RX indicates the number of bytes received and TX the number of bytes sent.
These amounts should match because all packets sent to the localhost should
be received without exception.

2. We launch the cluster (for comparison between simulations interested
send a video to go with a constant bit-rate or transmit always the same
video) and wait for the system to stop or get to the point you want.

3. We look again the number of bytes sent and received and subtract them
the measure we made in step 1.

Another interesting utility to measure bandwidth consumed can be "iftop"
because it gives us a continuous measure.

However, keep in mind that in our measurements come all transmissions over
localhost, including transmissions from the gatherer and peers to their
respective players (if any), but this does not matter for comparison
between simulations, as long as we use the same number of players in all
simulations and pass on the same video.

Greetings!

-- 
Vicente González Ruiz
Depto de Informática
Escuela Técnica Superior de Ingeniería
Universidad de Almería

Carretera Sacramento S/N
04120, La Cañada de San Urbano
Almería, España

e-mail: vruiz@xxxxxx
http://www.hpca.ual.es/~vruiz
tel: +34 950 015711
fax: +34 950 015486