ASSOLO is a new active probing tool for estimating available
bandwidth based on the concept of "self-induced congestion".
The tool features a new probing traffic profile called REACH
(Reflected ExponentiAl Chirp), which tests a wide range of
rates being more accurate in the center of the probing interval.
Moreover, the tool runs inside a real-time operating system and
uses some de-noising techniques to improve the measurement process.
GENERAL OVERVIEW
================
This code uses REACH UDP-trains of packets to estimate available
bandwidth (aka unused capacity) of a network path.
Instead of reinventing the wheel, ASSOLO re-uses the basic
low-level network packet sending functions of pathChirp 2.4.1,
another great measurement tool devoleped by Vinay Ribeiro,
Ryan Christopher King and Niels Kang Hoven (Rice University).
The SENDER (assolo_snd) and RECEIVER (assolo_rcv) modules run as
daemons on hosts at opposite edges of a path to be probed. Packet
trains travel from the SENDER to the RECEIVER.
We initiate the assolo probing using a third module, assolo_run,
which can be run on any host (called the MASTER). This module also
collects the results of the experiment and stores them in a file
locally. Thus experiments can be initiated and the results analyzed
from a central location in the Internet which runs the assolo_run
module.
The assolo_snd and assolo_rcv modules can be started on
different machines around the Internet and will run indefinitely. They
need not be restarted for each experiment.
chirps
SENDER ----------------> RECEIVER (assolo_rcv)
(assolo_snd) |
|
MASTER (assolo_run)
(starts experiment/collects results)
INSTALL INSTRUCTIONS
====================
Run the following:
1) ./configure
2) make
The following binaries will be generated:
Bin/<host_cpu>/assolo_rcv
Bin/<host_cpu>/assolo_snd
Bin/<host_cpu>/assolo_run
For example on your Linux box could be <host_cpu>=i686.
RUNNING EXPERIMENTS
===================
1) SENDER (needs to be run just once)
Bin/<host_cpu>/assolo_snd
Options:
-U <sender port, default=8365>
-h help (produces this output)
-v version
-D print debug information
NOTE ON PORT NUMBER: In case the default port number is already used
at the sender, try out other port numbers larger than 1024 using the
-U option. The receiver must then use the same port number with the -U
option.
2) RECEIVER (needs to be run just once)
Bin/<host_cpu>/assolo_rcv
Options:
-h Help
-v Version
-D print debug information
3) MASTER (needs to be rerun for each experiment)
Bin/<host_cpu>/assolo_run -S <sender> -R <receiver> -t <expt. duration (secs)>
** In case of interrupt coalescence on Gigabit networks use the -J option:
Example:
Bin/<host_cpu>/assolo_rcv -S <sender> -R <receiver> -t <expt. duration (secs)> -J 6
All Options:
-n <number of estimates to smooth over, default=11>
-d <decrease factor (>1), default=1.5>
-b <busy period length (integer >2), default=5>
-U <receiver port (chirp UDP), default=8365 (1024-65535)>
-h help: produces this output
-S sender host name or IP address
-R receiver host name or IP address
-J number of packets per Jumbo packet,default=1. In case of packet coalescence use values larger than 1, e.g. -J 6
-l lowest rate (Mbps) to probe at within chirp, default=10.000000Mbps. NOTE: by default assolo will find an appropriate probing range.
-u highest rate (Mbps) to probe at within chirp, default=200.000000Mbps
-p packet size <40-8200>,default=1000 bytes
-t duration of experiment(sec), default=600 sec
-s spread factor: ratio of consecutive inter-arrivals within a chirp, default=1.2
-a average probing rate (Mbps), default=0.3Mbps
-v version
-e treshold (default 5%)
-f filter (default type 0 - Vertical Horizontal Filter)
RESULTS
=======
At the MASTER, the file
<sender_name>_<receiver_name>_<time stamp>.instbw
will be generated in the directory from which the code is run.
FORMAT of the file:
<time_stamp> <avail-bw estimate (Mbps)>
Measurements _should_ be in chronological order. However, we suggest
to sort them using the standard *nix tool 'sort'.
An easy way to see results is to plot them. A simple script like:
close all; clear all;
trace = load('trace_filename.instbw'); % change filename here!
trace = sortrows(trace, 1);
time = trace(:, 1);
time = time - time(1)
avail_bw = trace(:, 2);
plot(time, avail_bw);
hold on;
set(gca, 'YLim', [75 100], 'XLim', [0 30]); xlabel('Time');
ylabel('Available Bandwidth');
enable you to see measured available bandwidth using Octave/Gnuplot.
CORRESPONDENCE
==============
Please do send your comments about the performance of this available
bandwidth estimation tool, and any changes you feel would make the
tool more convenient or user friendly.
Contact: Emanuele Goldoni, emanuele.goldoni@unipv.it