From Ethernet to Wi-Fi: Flow Feature Selection and Construction for Traffic Classification
Authors: Francisco Rau, Petia Georgieva, Carlos Herranz, Iñaki Val, Joaquin Perez
Organizations: MaxLinear, Inc., Valencia, Spain · Electronic Engineering Department, Universitat de València, Valencia, Spain · Institute of Electronics and Informatics Eng. of Aveiro (IEETA), University of Aveiro, Portugal
Flow-based traffic classifiers trained on Ethernet data may lose accuracy when applied to Wi-Fi traffic. This paper proposes a five-stage procedure for selecting and constructing features that enable Wi-Fi flow classification using models trained only on Ethernet data. The procedure removes the transport protocol identifier, examines rate dependence, compares feature distributions and the information each feature provides for the application classes, reduces redundancy, and constructs normalized packet-size and temporal features. Ethernet and Wi-Fi traffic are simulated in ns-3, with Wi-Fi using Best Effort access category. Labelled Wi-Fi data from six development scenarios are used for feature design, while a separate scenario is reserved for final testing. The evaluation compares feature sets, examines threshold sensitivity, and analyses classification errors under different traffic conditions.
Figures & tables
Rate for training
Ethernet
Wi-Fi
ID
Application (classes)
(Mb/s)
Train
Test
S1–S6
S7
VP
VoIP
0.10
216
69
1,620
270
VC
Video Conference
3
216
69
2,160
270
GM
Gaming (Quake 3)
0.11
216
69
1,890
270
VS
Video Streaming (DASH)
20
216
69
1,876
540
BT
Bulk TCP
10
216
69
742
270
TABLE I: Common application classes and dataset windows.
Fig. 1: Distribution shift and class information for 16 features. Blue: retained; red: removed. Dashed lines show the KS threshold (0.30) and MI-ratio thresholds (0.60 and 1.00). Shaded areas show removal regions.
Original
Constructed
sorig
sconstr
std_pkt_size
min_max_ratio
0.673
0.027
burstiness
pkt_size_range_r
0.667
0.493
max_iat
activation_fraction
0.803
0.803
min_iat
iat_min_ratio
0.803
0.766
TABLE II: Rate-dependence scores before and after feature construction ( s(X) from Section II-B2 ).
Feature
Formula
rms_pkt_size
s2
max_pkt_size
smax
switching_ratio
nΔs/(N−1)
min_max_ratio
smin/smax
pkt_size_range_r
(smax−smin)/sˉ
activation_fraction
1−τmax/T
TABLE III: Final seven dimensional feature space.
Scenario
Network
VP
VC
GM
VS
BT
IT
IU
BU
Flows
Windows
S1
One BSS
0.10
5, 10
0.11, 0.11
20
15
–
200, 200
100
10
2,699
S2
One BSS
0.10
5, 10
0.11
20
15
unb.
200, 200
100
10
2,691
S3
Two BSSs *
0.10
5
0.11
20
–
–
–
–
4
1,080
S4
Two BSSs *
0.10
5
0.11
20, 10
–
–
–
–
5
1,350
S5
Two BSSs *
0.10
5
0.11
20
–
–
–
300
5
1,346
S6
Two BSSs *
0.10
5
0.11
20
15
–
–
300
6
1,552
TABLE IV: Wi-Fi scenarios: downlink flow rates (Mb/s) by application ID from Table I .
Fig. 2: Accuracy after each feature selection and construction stage (Section II-B ; Ratios: feature construction) on the four evaluation sets of Section III-C . Ethernet training accuracy is 100% at every stage. Where the two Wi-Fi lines overlap, the upper value is S7 and the lower value is S1–S6.
S1–S6
S7
Class
29
7
29
7
Bulk TCP
63.1
98.2
0.0
100
IPERF TCP
93.0
38.9
99.3
99.3
Video Streaming
49.8
99.7
98.3
100
Other five classes
100
100
100
100
Accuracy
88.48
98.28
88.44±0.27
99.92±0.18
TABLE V: Recall (%) per class, accuracy, Macro-F1 with 29 and 7 features.
S2
S7
Downlink load requested by the other flows (Mb/s)
≈ 550
≈ 120
IPERF TCP throughput (Mb/s)
12
197
Mean downlink delay of IPERF TCP at the AP (ms)
147
8
IPERF TCP windows with activation_fraction <0.98
63%
0.7%
Median activation_fraction of Video Streaming
0.97
0.72
IPERF TCP recall (%)
38.9
99.3
TABLE VI: Traffic conditions in S2 and S7, and IPERF TCP recall with seven features.
School of Cyber Science and Engineering, Southeast University, Nanjing, China · School of Computer Science and Engineering, Southeast University, Nanjing, China