Index of /szym/more

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How to build and run MORE (MAC-independent Opportunistic Routing and Encoding)?

MORE -- MAC-independent Opportunistic Routing and Encoding

Features

As packaged here, MORE supports a limited set of features:

unicast and multicast (scripts support unicast only)
single flow only
static routing (i.e., there is no routing protocol)
uniform synthetic traffic only (the batches are generated within Click)

We are planning to address the missing features in the near future, depending on the demand.

Important Notes

MORE sets the wireless interface (e.g.,ath0) in monitor mode. Such a "raw" interface is not suitable for Linux routing, therefore ath0 cannot be used to control the testbed node remotely. Although the madwifi-ng driver allows multiple VAPs (and it's also feasible to modify MORE to run in station mode), it is highly recommended that a separate physical network interface is used to control the node so that experimental traffic does not interfere with control.
For effective network coding, MORE keeps the output buffering to minimum. However, this significantly increases the CPU overhead of user-kernel switching in this user-level prototype. This might substantially skew results, when comparing to in-kernel implementation (e.g., native Linux routing), especially when using high wireless bit-rates. It is highly recommended that no bit-rates faster than 6Mbps are used for comparison.

Installing

As implemented here, MORE is a userspace program that communicates with the wireless network interface via raw sockets to route its packets from the source to the destination.

MORE has been built on Click modular router and tested on Atheros 802.11 a/b/g cards driven by the MadWifi driver on Linux 2.6. Running on other systems will require some porting.

To truly test MORE, you will need at least 3 machines (source, destination and a forwarder) equipped with an Atheros wireless interface. To sum up, the steps required are:

install madwifi-ng on testbed machines
build userlevel Click with MORE
place click binary, config.py and startup.sh on testbed machines (default location is ~root/more)
place remaining scripts (or the whole conf directory) in your environment PATH on your experiment driving machine
create a nodes listing file and run experiments

MadWifi

MadWifi is only needed to run Click with MORE, not build it.

Follow the download instructions from madwifi-project.org. MORE should work fine with both madwifi-old and madwifi-ng. However, this package has been specifically prepared for the release madwifi-0.9.3.3. Follow the installation instructions from the driver package on your testbed machines.

If you previously had madwifi installed, you might have to remove the old modules. That could require bringing the interface down and unloading the module ath_pci.

Click

Follow the download instructions from ucla.edu. This package was tested on Click releases 1.5.0 and 1.6.0.

To build Click with MORE, you need to place MORE source code as a subdirectory to one of the enabled subdirectories in the /elements tree. For example you can place the source files under elements/local, but do not forget to --enable-local in the configure. Alternatively, place the source files in a subdirectory of /elements/wifi.

MORE uses very few elements from click -- from userlevel, standard, ethernet, and wifi. Make sure that these element directories are enabled. MORE was tested in userlevel only. You can disable linuxmodule, app, aqm, tcpudp, ip, icmp for faster build. If you are building on a different machine than the testbed, you might consider adding LDFLAGS=--static.

Build the userlevel click binary and place it on your testbed machines.

Router configuration

A core component of the package is the script config.py. When executed on a testbed machine, it ensures that the wireless interface is in the monitor ("raw") mode and generates a a Click configuration file including both MORE and a straw-man single-path router (SPP).

Routing

To compute static routing, you need to measure all-pair delivery probabilities in the selected transmitter configuration (channel, bitrate, tx power). Included in the package is a simple tool links.py that takes care of that.

Like other scripts in this package, links.py uses nodes.py and a common format of node list for management -- for each node in your testbed the list includes the line:

[IP] [MAC] [HOSTNAME]

The scripts assume you can ssh root@IP without passwords (e.g., using keys). MAC is the hardware address of the wireless device and HOSTNAME is for convenience. To find the MAC you can run (on the subject testbed machine):

./config.py > /dev/null

With default settings, it should read:

using wifi0 / ath0 MAC 00:11:22:33:44:55

NOTE: the assumed directory for click, config.py and startup.sh is /root/more. To change it, update RUNTIME_DIR in nodes.py. The default name for the node list is ./nodes.

The link measurement format used for computation is:

[transmitter] [receiver] [bitrate] [delivery-prob]

Where bitrate is the IEEE (2x) bit-rate (i.e, 5.5Mb/s is bitrate 11).

Example

To install Madwifi:

make
make install

To configure and build click (assuming MORE is under elements/local):

./configure --enable-wifi --enable-local
make
# copy userlevel/click to the testbed machines

To setup runtime environment:

# create the 'nodes' file, e.g.
10.0.0.1 00:AA:BB:CC:DD:EE host1
10.0.0.2 00:AA:BB:CC:DD:FF host2
# put click, config.py and startup.sh in your runtime dir on the testbed

To setup all nodes on a common channel, e.g. 4, and (and to quickly check if the 'nodes' file is correct):

exec.py nodes 'iwconfig ath0 channel 4'

To measure links at 1Mb/s:

links.py -r 2 -o links2
# it takes a while!
# output in links2 could look like this:
host1 host2 2 0.5
host2 host1 2 1.0

To run experiment:

quickrun.py links2 host1 host2 spp
quickrun.py links2 host1 host2 more
# this writes the routing configuration to (spp|more).feed
# executes it
# and dumps the counters' readings to (spp|more).stats

The resulting Python-parsable .stats file contains a dictionary storing, for each hostname in nodes, a list of 5 strings: outgoing DATA packets, outgoing ACK packets, incoming packets, packets received (at sink), average rate of packets received (at sink). For example:

{
'host1' : ['4200', '0', '64', '0', '0'] ,
'host2' : ['0', '64', '4188', '4160', '70.92'] ,
}

We see host2 received 4160 packets at average rate of 70.92 per second.

NOTE: Your mileage may vary. The throughput gain of MORE strongly depends on the diversity in the network. For example, if both MORE and SPP transmit directly to the destination (1-hop), then there is no opportunistic gain to be expected. Generally, we can expect better results, if the nodes in the network have high degrees of low quality links.

Change Log

2009-07-16

Renamed _IO to avoid preprocessor macro clash on Debian.

2009-04-08

Added notes on setting the channel.

2008-07-25

Added "Important Notes".

2007-11-27

Released.