Post on 25-Jun-2020
15th June 2016, Wednesday University of Washington, Seattle, USA
Mohit P. Tahiliani, Dharmendra Kumar Mishra, Pranav Vankar
Wireless Information Networking Group,
National Institute of Technology Karnataka, Surathkal, India
tahiliani@nitk.ac.in
8th Annual Workshop on ns-3 (WNS3 2016)
TCP Evaluation Suite for ns-3
Outline of the presentation
❑ Motivation
❑ Existing implementations
❑ Design and implementation of tcp-eval in ns-3
❑ User interaction with ns-3 tcp-eval
❑ Comparing TCP extensions in ns-3
❑ Results and discussions
❑ Validation issues
❑ Conclusions and the next goals
15th June 2016, Wednesday University of Washington, Seattle, USA
Motivation
❑ Congestion control algorithms continue to evolve . . .
❑ . . . and so do TCP extensions!
❑ Problem: not feasible to evaluate every TCP extension exhaustively
❑ Potential solution:
- derive some initial results and study the behaviour
- consider the promising ones for thorough evaluation
What is TCP Evaluation Suite?
- a set of well-defined, standard test cases to compare TCP extensions
- initially proposed by Transport Modeling Research Group (TMRG)
- modified by Internet Congestion Control Research Group (ICCRG)
- widely used today for evaluating new TCP extensions
15th June 2016, Wednesday University of Washington, Seattle, USA3
Existing implementations
❑ Wang, G., Y. Xia, and D. Harrison. “An NS2 TCP evaluation tool.”
draftirtf-tmrg-ns2-tcp-tool, IETF Internet Draft (expired) (2007).
- Two versions of code.
- Version 2 source: https://sourceforge.net/projects/tcpeval
❑ Shimonishi, Hideyuki, M. Y. Sanadidi, and Tutomu Murase. “Assessing
Interactions among Legacy and High-Speed TCPs.” PFLDnet 2007 (2007).
- designed for evaluating High-speed TCP extensions using ns-2
- Source: http://nrlweb.cs.ucla.edu/tcpsuite/index.html
15th June 2016, Wednesday University of Washington, Seattle, USA4
Existing implementations
❑ Li, Yee-Ting, Douglas Leith, and Robert N. Shorten. “Experimental
evaluation of TCP protocols for high-speed networks.” Networking, IEEE/
ACM Transactions on 15.5 (2007): 1109-1122.
- designed for evaluating High-speed TCP extensions using ns-2
- Source: http://www.hamilton.ie/net/eval/hi2005.htm
❑ Hayes, D., Ros, D., Andrew, L. and S. FLoyd, “Common TCP Evaluation
Suite” draft-irtf-iccrg-tcpeval-01, IETF Internet Draft (expired) (2015).
- The latest draft on TCP Evaluation Suite
- Source: https://bitbucket.org/hayesd/tcp-evaluation-suite-public
15th June 2016, Wednesday University of Washington, Seattle, USA5
Design and implementation of ns-3 tcp-eval
❑ Implemented as a separate model called tcp-eval in ns-3 (~5500 lines)
❑ Topologies:
- Dumbbell (single bottleneck topology)
- Parking lot (multiple bottlenecks topology)
❑ Traffic types:
- Long lived FTP
- Streaming video
- Interactive voice
❑ Performance metrics:
- Aggregate link utilization
- Mean queue length, and Packet drop rate
15th June 2016, Wednesday University of Washington, Seattle, USA6
Design and implementation of ns-3 tcp-eval
15th June 2016, Wednesday University of Washington, Seattle, USA
Figure: Class diagram of tcp-eval in ns-3
7
User interaction with ns-3 tcp-eval
15th June 2016, Wednesday University of Washington, Seattle, USA
Figure: User interaction diagram of tcp-eval for dumbbell scenario
User
drive-dumbbell.cc
Results
point-to-point-dumbbell.ccdumbbell-topology.cc
eval-stats.cc
create-traffic.cc
traffic-parameters.cc
configure-topology.cc
1
2
3
4
5
6
7
8Core modules
Configuration module
Supporting module
Legends
8
User interaction with ns-3 tcp-eval
15th June 2016, Wednesday University of Washington, Seattle, USA
Figure: User interaction diagram of tcp-eval for parking-lot scenario
User
drive-parking-lot.cc
Results
point-to-point-parking-lot.ccparking-lot-topology.cc
eval-stats.cc
create-traffic.cc
traffic-parameters.cc
configure-topology.cc
1
2
3
4
5
6
7
8
Core modules
Configuration module
Supporting module
Legends
9
Comparing TCP extensions in ns-3
❑ Five TCP extensions: Tahoe, Reno, NewReno, Westwood, Westwood+
❑ Three scenarios:
- Varying bottleneck bandwidth
- Varying RTT
- Varying the number of FTP flows
❑ Three Performance metrics:
- Link utilization
- Mean queue length
- Packet drop rate
❑ Output:
- PDF containing graphs (LaTex must be installed!)
15th June 2016, Wednesday University of Washington, Seattle, USA10
Results and discussions: varying bottleneck bandwidth
15th June 2016, Wednesday University of Washington, Seattle, USA
0
20
40
60
80
100
1 10 100
Lin
k U
tiliz
atio
n (
%)
Bandwidth (Mbps) Log Scale
Link Utilization with Bandwidth Changes
TahoeReno
NewrenoWestwood
Westwood+ 0
20
40
60
80
100
1 10 100
Lin
k U
tiliz
atio
n (
%)
Bandwidth (Mbps) Log Scale
Link Utilization with Bandwidth Changes
TahoeReno
NewrenoWestwood
Westwood+
Dumbbell topology Parking lot topology
11
Results and discussions: varying bottleneck bandwidth
15th June 2016, Wednesday University of Washington, Seattle, USA
Dumbbell topology Parking lot topology
0
20
40
60
80
100
1 10 100
Mean Q
ueue
Length
(%
)
Bandwidth (Mbps) Log Scale
Percent of Mean Queue Length with Bandwidth Changes
TahoeReno
NewrenoWestwood
Westwood+
0
20
40
60
80
100
1 10 100
Mean Q
ueue
Length
(%
)
Bandwidth (Mbps) Log Scale
Percent of Mean Queue Length with Bandwidth Changes
TahoeReno
NewrenoWestwood
Westwood+
12
Results and discussions: varying bottleneck bandwidth
15th June 2016, Wednesday University of Washington, Seattle, USA
Dumbbell topology Parking lot topology
0
2
4
6
8
1 10 100
Pack
et D
rop R
ate
(%
)
Bandwidth (Mbps) Log Scale
Packet Drop Rate with Bandwidth Changes
TahoeReno
NewrenoWestwood
Westwood+
0
2
4
6
8
1 10 100
Pack
et D
rop R
ate
(%
)
Bandwidth (Mbps) Log Scale
Packet Drop Rate with Bandwidth Changes
TahoeReno
NewrenoWestwood
Westwood+
13
Results and discussions: varying RTT
15th June 2016, Wednesday University of Washington, Seattle, USA
Dumbbell topology Parking lot topology
0
20
40
60
80
100
0.01 0.1 1
Lin
k U
tiliz
atio
n (
%)
RTT (s) Log Scale
Link Utilization with RTT Changes
TahoeReno
NewrenoWestwood
Westwood+ 0
20
40
60
80
100
0.01 0.1 1
Lin
k U
tiliz
atio
n (
%)
RTT (s) Log Scale
Link Utilization with RTT Changes
TahoeReno
NewrenoWestwood
Westwood+
14
Results and discussions: varying RTT
15th June 2016, Wednesday University of Washington, Seattle, USA
Dumbbell topology Parking lot topology
0
10
20
30
40
50
60
70
80
90
100
0.01 0.1 1
Mean Q
ueue
Length
(%
)
RTT (s) Log Scale
Percent of Mean Queue Length with RTT Changes
TahoeReno
NewrenoWestwood
Westwood+
0
10
20
30
40
50
60
70
80
90
100
0.01 0.1 1
Mean Q
ueue
Length
(%
)
RTT (s) Log Scale
Percent of Mean Queue Length with RTT Changes
TahoeReno
NewrenoWestwood
Westwood+
15
Results and discussions: varying RTT
15th June 2016, Wednesday University of Washington, Seattle, USA
Dumbbell topology Parking lot topology
0
2
4
6
8
0.01 0.1 1
Pack
et D
rop R
ate
(%
)
RTT (s) Log Scale
Packet Drop Rate with RTT Changes
TahoeReno
NewrenoWestwood
Westwood+
0
2
4
6
8
0.01 0.1 1
Pack
et D
rop R
ate
(%
)
RTT (s) Log Scale
Packet Drop Rate with RTT Changes
TahoeReno
NewrenoWestwood
Westwood+
16
Results and discussions: varying number of FTP flows
15th June 2016, Wednesday University of Washington, Seattle, USA
Dumbbell topology Parking lot topology
0
20
40
60
80
100
1 10 100
Lin
k U
tiliz
atio
n (
%)
FTP Log Scale
Link Utilization with FTP Changes
TahoeReno
NewrenoWestwood
Westwood+ 0
20
40
60
80
100
1 10 100
Lin
k U
tiliz
atio
n (
%)
FTP Log Scale
Link Utilization with FTP Changes
TahoeReno
NewrenoWestwood
Westwood+
17
Results and discussions: varying number of FTP flows
15th June 2016, Wednesday University of Washington, Seattle, USA
Dumbbell topology Parking lot topology
0
20
40
60
80
100
1 10 100
Mean Q
ueue
Length
(%
)
FTP Log Scale
Percent of Mean Queue Length with FTP Changes
TahoeReno
NewrenoWestwood
Westwood+ 0
20
40
60
80
100
1 10 100
Mean Q
ueue
Length
(%
)
FTP Log Scale
Percent of Mean Queue Length with FTP Changes
TahoeReno
NewrenoWestwood
Westwood+
18
Results and discussions: varying number of FTP flows
15th June 2016, Wednesday University of Washington, Seattle, USA
Dumbbell topology Parking lot topology
0
2
4
6
8
1 10 100
Pack
et D
rop R
ate
(%
)
FTP Log Scale
Packet Drop Rate with FTP Changes
TahoeReno
NewrenoWestwood
Westwood+
0
2
4
6
8
1 10 100
Pack
et D
rop R
ate
(%
)
FTP Log Scale
Packet Drop Rate with FTP Changes
TahoeReno
NewRenoWestwood
Westwood+
19
Validation issues
❑ Original tcp-eval is implemented in older version of ns-2 (ns-2.31!)
❑ ns-2.31 did not have many new TCPs
❑ Hence, tcp-eval contained custom implementations of new TCPs
❑ Latest tcp-eval implementation in ns-2 is on ns-2.35
❑ But there are several bugs identified, and its development has stopped
❑ Started aligning our implementation with that of tcp-eval for ns-2.35
15th June 2016, Wednesday University of Washington, Seattle, USA20
Conclusions and the next goals
❑ A ns-3 model for tcp-eval has been implemented, but not validated.
❑ Automates the cycle from setting parameters to collecting results
❑ Steps to reproduce the results have been provided.
Next goals:
❑ Align the model to latest version of tcp-eval (2016 summer project!)
❑ Evaluate the model by comparing its results to those obtained from ns-2
❑ Include support for more topologies (wireless) and AQM algorithms
❑ Provide per-flow analysis to the user.
15th June 2016, Wednesday University of Washington, Seattle, USA21
Acknowledgement
❑ All the reviewers, for the encouraging reviews!
❑ Tom Henderson, for guiding us through the validation procedure.
❑ All developers of TCP extensions in ns-3.
❑ The entire ns-3 community.
❑ Our research group at NITK Surathkal.
15th June 2016, Wednesday University of Washington, Seattle, USA22
Thank you.