Figure 3a (Page 7) is used to show the the affect of network interference in network switches and the extent to which QJump can fix it. It also gives an indication of the limits of QJump's performance. It shows that prioritization inside of switches does not resolve all interference.

WARNING This experiment requires use of an Endace DAG 9.2x2 or similar capture card and two passive optical taps for high fidelty network capture.

Figure 3a

Software Required

In addition to these general software requirements, we also used:

• QJump kernel module
• QJump application utility
• ping (as packaged with Ubuntu 12.05/14.04)
• iperf (as packaged with Ubuntu 12.05/14.04)
• dag-capture as found in qjump-camio-tools
• dag-analyse as found in qjump-camio-tools
• dag-join as found in qjump-camio-tools

Physical Configuration

The basic physical network configuration is described here. In this experiment the following configuration was used:

• ping was run between H8 (Quorum201) and H10 (Quorum205)
• iperf 1 was run between H7 (Quorum301) and H10 (Quorum205)
• iperf 2 was run between H3 (Backstroke) and H12 (Quourm207)
• dag_capture was run on H9 (Quorum208) to capture ping traffic in the network. Optical taps were placed on the output of H8 and the input to H10.

Sofware Configuration

Iperf servers and clients were configured respectively:

iperf -s -i1 -P 3

iperf -c 10.10.0.XXX -t 99999 -i 1 -P 3

Ping was configured as follows:

sudo ping 10.10.0.2 -i 0.01

When QJump was enabled, it was configured as follows

timeq=15 bytesq=1550 p7rate=300 p6rate=0 p5rate=0 p4rate=150 p3rate=30 p2rate=15 p1rate=5 p0rate=1

To run ping with QJump enabled, it was run with our application utility:

./qjau.py -p 7 -c "sudo ping 10.10.0.2 -i 0.01"

The DAG capture tool was configured as follows:

sudo ./bin/dag_capture -s 10000 -t 0

Raw Data

Our original unprocessed datasets can be found here (1.92MB). There are 30 files in the archive. Each file contains ERF records from the DAG capture. The files come in pairs: each pair contains a 201 and 205 file which represents the sending and recieving sides. The file names are of the form:

• ping201205_20[1|5]_[0-4] - Ping Trace captured between 201 and 205 with no other traffic running. 5 trails were run.
• ping201205_iperf301205_iperfBS207_20[1|5]_[0-4] - Ping Trace captured between 201 and 205 with iperf traffice causing interference. 5 trails were run.
• ping201205_iperf301205_iperfBS207_TCP7_20[1|5]_[0-4- Ping Trace captured between 201 and 205 with iperf traffice causing interference and QJump resolving it. 5 trails were run.

Processing and plotting the results

The processing and plotting scripts can be found here. The processing scripts rely on the presence of dag_analyse and dag_join tools in order to process the binary files. Instructions for obtaining and building these tools can be found here .

./process_dag.sh ../data/ping_dag/ping201205_ 0 ../qjump-camio-tools/

Which will produde the file out_ping201205_0.lats. This can then be plotted along with the other files with:

python plot_ping_dag_latency_cdfs.py ../data/ping_dag/out_ping201205_0.lats ../data/ping_dag/out_ping201205_iperf301205_iperfBS207_0.lats iperf ping ../data/ping_dag/out_ping201205_iperf301205_iperfBS207_TCP7_0.lats qjump figure3a