Hi!

This is regarding multiple gates in o11s. My team and I found the idea
interesting and decided to explore it at a greater length. We have used the
Click modular router to set up an SDN with multiple gates in the mesh
network. We've conducted a few experiments and the gains using two gates
seem to be additive.

We were wondering if this would be beneficial and feasible for the current
implementation of o11s as the gains seem to be promising. There also seem
to be valid use cases as multiple gateways in close proximity are pretty
common in apartment societies, to name a place. Community networks may also
be a good ground for such deployments. If there is a way this could make it
into the kernel, we are more than willing to put in the required effort.
All of your suggestions are welcome and I am sure they can help us make the
most out of this project.

We have effectively moved away from single associations , which is the
convention, towards a model of multiple associations, where each node in
the mesh can be "connected" to several internet access gates at the same
time. This is being done on a per flow basis so that we can route all the
traffic associated with a single socket through one gateway. This is done
in order to not confuse a server on the remote end as it might otherwise
treat packets from a different gate as a DoS attempt.

We've been experimenting with a few types of gates such as an Android phone
tethered via USB, which effectively replicates a USB dongle, and also wired
ethernet connections. We've also conducted a few experiments using o11s as
the local network with Click scripts running on each machine. The
experiments were attempts at replicating the real Internet by using a local
http server and a local Bittorrent tracker.

Details of the local experiment follow with an HTTP webserver (nginx) :

We host a single 1 M file on the server (S) which is in turn  accessible by
two machines (G1 and G2, the two "gates"). The client (C) wants to download
multiple copies of this 1M file from the server,
using these two paths :

C -> G1 -> S
C -> G2 -> S

Each of these paths resemble a single internet connection. The aim of this
experiment was to study how the network reacts when we  try to use both
connections (paths) at the same time for higher throughput.

We varied the link speeds in the scenario and plotted a graph for the link
speeds versus the time it took to download files using a single G1 path, a
single G2 path and both paths respectively.

The number of simultaneous file downloads was set to 16 and the link speeds
were varied from 100 kbps to 1400 kbps using the tc utility on  both the
intermediate machines (G1 and G2).

The gains are linear till a point where the hardware link seems to
saturate.

This is the public repository on github :
https://github.com/scar1337/nodeman

It has a README and setup scripts which will help you set up and hack away
at the project in case you are interested. You will need our modified
version of click which is available at https://github.com/scar1337/click

Needless to say, all of the machines do this using a single interface
instead of multiple interfaces that most research papers talk about. Thanks
for reading the long mail. I hope this can be extended somehow so that o11s
networks can use all available bandwidth and experience maximized
throughput.

Regards,
Ashish Gupta
_______________________________________________
Devel mailing list
[email protected]
http://lists.open80211s.org/cgi-bin/mailman/listinfo/devel

Reply via email to