NS-3 For Evaluating INT Signals for Congestion Control

This repo is a copy of ns-3.36 with changes to support INT signaling, evaluation of R+ CCAs.

Simulator Instructions

For basic operation of the simulator (building, configuring, etc.), refer to the ns instructions below.

Note: it is recommended to configure the build to ignore examples unless you are planning to use them (./ns3 configure --disable-examples)

Requirements

./ns3 requires cmake and g++

The R+ support also has the additional requirements: protobuf-compiler libboost-all-dev

Running R+ Outputs

Individual simulations

R+ simulations are run with the single-link-v2.cc script in the scratch/ dir. All arguments can be seen in the code, but as an example, one may run it with:

./ns3 run rplus-sim/single-link-v2.cc -- --cca=ns3::TcpRemy --netfile=/path/to/config-default.cfg --samplesize=1 --whiskerfile=/path/to/rplus/results/cfg-default-results-dir/queue/cfg-default-intq.4 --configruns=10 --intenabled=True --linkintutil=True --linkinterval=10 --delaycoef=1 --tputcoef=1 --byteswitched=False --simtime=11.0 --savewhiskerstats=False --seed=1

Notes:

• The script is usually run with samplesize=1 so that only one (seeded) configuration is run each time. To run the same configuration multiple times, use the configruns parameter.
• intenabled makes it so that nodes add/edit the INT header (individual signals do not need to be enabled/disabled)

Running many simulations in parallel

To run many simulations in parallel with different parameters, you can use the sem python package. Python scripts using this package can be found in scripts/.

As an example, you may run rplus-campaign-mg-mt.py as follows:

python3 rplus-campaign-mg-mt.py -t "int,intq,intl,noint" -g "0,1,2,3,4" -w cfg-default-results-dir -cf config-default.cfg -s optional-suffix-to-result-filenames

This will run 200 simulations of the R+ outputs in the directory with the name with the name cfg-default-results-dir for each selected generation (0-4) and each signal set listed with the network config config-default.cfg (each signal set is expected to have its own named subdirectory).

Notes:

• The script expects there to be a single directory with all R+ outputs to test. Within this, there should be a subdir for each signal set that contains all generations.

  • Example (for the above example command):

    cfg-default-results-dir/
      -- /int/
        -- cfg-default-int.0
        -- cfg-default-int.1
        -- ...
      -- /intq/
        -- cfg-default-int.0
        -- cfg-default-int.1
        -- ...
      -- ...
  

• You must set some file paths at the top of the script for your environment.

Main Changes

Here, we note the main modifications over baseline ns3 for easier changes to our work:

• src/internet/model/tcp-remy.cc implements R+ outputs as a CCA
  • src/internet/model/remy contains additional files necessary for support
• src/internet/model/tcp-socket-base.cc and src/internet/model/tcp-socket-state.cc were modified slightly to support INT signaling (and allowing the CCA to access it)
• src/network/model/int-packet-tag.cc adds a tag that hosts can use to record INT metadata of a packet even after the INT header is stripped
• src/point-to-point/model/int-header.cc implements the INT header
• src/point-to-point-net-device/model/point-to-point-net-device.cc contains the code for how a node (switch) can read and update the INT header of a packet
• scratch contains the top-level simulator script as well as some additional utils (including how utility is traced and calculated)

The Network Simulator, Version 3

Table of Contents:

1. An overview
2. Building ns-3
3. Running ns-3
4. Getting access to the ns-3 documentation
5. Working with the development version of ns-3

Note: Much more substantial information about ns-3 can be found at https://www.nsnam.org

An Open Source project

ns-3 is a free open source project aiming to build a discrete-event network simulator targeted for simulation research and education. This is a collaborative project; we hope that the missing pieces of the models we have not yet implemented will be contributed by the community in an open collaboration process.

The process of contributing to the ns-3 project varies with the people involved, the amount of time they can invest and the type of model they want to work on, but the current process that the project tries to follow is described here: https://www.nsnam.org/developers/contributing-code/

This README excerpts some details from a more extensive tutorial that is maintained at: https://www.nsnam.org/documentation/latest/

Building ns-3

The code for the framework and the default models provided by ns-3 is built as a set of libraries. User simulations are expected to be written as simple programs that make use of these ns-3 libraries.

To build the set of default libraries and the example programs included in this package, you need to use the tool 'ns3'. Detailed information on how to use ns3 is included in the file doc/build.txt

However, the real quick and dirty way to get started is to type the command

./ns3 configure --enable-examples

followed by

./ns3

in the directory which contains this README file. The files built will be copied in the build/ directory.

The current codebase is expected to build and run on the set of platforms listed in the release notes file.

Other platforms may or may not work: we welcome patches to improve the portability of the code to these other platforms.

Running ns-3

On recent Linux systems, once you have built ns-3 (with examples enabled), it should be easy to run the sample programs with the following command, such as:

./ns3 run simple-global-routing

That program should generate a simple-global-routing.tr text trace file and a set of simple-global-routing-xx-xx.pcap binary pcap trace files, which can be read by tcpdump -tt -r filename.pcap The program source can be found in the examples/routing directory.

Getting access to the ns-3 documentation

Once you have verified that your build of ns-3 works by running the simple-point-to-point example as outlined in 3) above, it is quite likely that you will want to get started on reading some ns-3 documentation.

All of that documentation should always be available from the ns-3 website: https://www.nsnam.org/documentation/.

This documentation includes:

• a tutorial

• a reference manual

• models in the ns-3 model library

• a wiki for user-contributed tips: https://www.nsnam.org/wiki/

• API documentation generated using doxygen: this is a reference manual, most likely not very well suited as introductory text: https://www.nsnam.org/doxygen/index.html

Working with the development version of ns-3

If you want to download and use the development version of ns-3, you need to use the tool git. A quick and dirty cheat sheet is included in the manual, but reading through the git tutorials found in the Internet is usually a good idea if you are not familiar with it.

If you have successfully installed git, you can get a copy of the development version with the following command:

git clone https://gitlab.com/nsnam/ns-3-dev.git

However, we recommend to follow the Gitlab guidelines for starters, that includes creating a Gitlab account, forking the ns-3-dev project under the new account's name, and then cloning the forked repository. You can find more information in the manual.