Ana Klimovic and Chuan-Zheng Lee
CS 244 (Advanced Topics in Networking), Stanford University

This repository contains code used in a CS 244 class project to reproduce the results of Matthew P. Grosvenor et al. in "Queues Don’t Matter When You Can JUMP Them!", presented at the 12th USENIX Symposium on Networked Systems Design and Implementation (NSDI ’15).

1. Start an Amazon EC2 instance from the CS244-Spr15-Mininet (ami-cba48cfb) Amazon machine image. (It's listed under Community AMIs. You must be on the US West (Oregon) region to find this.) We used a c3.xlarge instance. Log into the instance.

   (For more details, see the CS 244 page on EC2 setup.)

2. Clone this repository, the QJump traffic control (TC) module and the QJump Application Utility. Also, clone our modified version of Mininet, but clone it to the directory mininet_qjump.

    $ git clone https://github.com/anakli/cs244-qjump.git
    $ git clone https://github.com/czlee/qjump-tc.git
    $ git clone https://github.com/camsas/qjump-app-util.git
    $ git clone https://github.com/czlee/mininet.git mininet_qjump
   

   (The QJump TC module is slightly modified from the original: it uses the kernel clock rather than the processor's timestamp counter. A pull request is planned, eventually. Mininet was modified to create eight transmit queues on each interface, rather than just one. At the moment it's hard-coded, but a more configurable pull request is also planned, eventually.)

3. Build the QJump TC module:

    $ cd qjump-tc
    $ make
    make -C /lib/modules/3.13.0-48-generic/build M=/home/ubuntu/qjump-tc modules
    make[1]: Entering directory `/usr/src/linux-headers-3.13.0-48-generic'
      CC [M]  /home/ubuntu/qjump-tc/sch_qjump.o
      Building modules, stage 2.
      MODPOST 1 modules
      CC      /home/ubuntu/qjump-tc/sch_qjump.mod.o
      LD [M]  /home/ubuntu/qjump-tc/sch_qjump.ko
    make[1]: Leaving directory `/usr/src/linux-headers-3.13.0-48-generic'
   

4. Build the QJump application utility:

    $ cd ../qjump-app-util
    $ make
    rm -f qjump-app-util.so*
    gcc -O3 -fPIC -shared -Werror -Wall -o qjump-app-util.so  qjump-app-util.c -ldl
   

5. Create symbolic links to the TC module and application utility from the cs244-qjump directory (or just copy it over if you prefer):

    $ cd ../cs244-qjump
    $ ln -s ../qjump-tc/sch_qjump.ko sch_qjump.ko
    $ ln -s ../qjump-app-util/qjump-app-util.so qjump-app-util.so
   

6. Install the VLAN configuration program.

    $ sudo apt-get update
    $ sudo apt-get install vlan
   

7. Run!

    $ sudo python qjump.py --all
   

   Results will be stored in a timestamped subdirectory of the results/ directory. A symlink to the most recent results directory is placed at last.

The default setting is to run tests for 10 seconds with 10 Mbit/s links using the topology used by Grosvenor et al.. Some useful options:

• --time=TIME, -t=TIME: how long to run the experiment
• --bw-link=BANDWIDTH: the bandwidth of various links
• --timeq=EPOCH: a network epoch length, in microseconds
• --bytesq=BYTESQ: how many bytes a high-priority sender can send in a network epoch

To see all options:

$ python qjump.py --help