An Investigation into Transport Protocols and Data Transport ...

8.3. Results 171
4000
3500
3000
HTCP 1
HTCP 2
250
200
HTCP 1
HTCP 2
cwnd (packets)
2500
2000
1500
1000
500
Goodput (mbit/sec)
150
100
50
0
100 150 200 250 300 350 400
Time (seconds)
0
100 150 200 250 300 350 400
Time (seconds)
(a) Congestion Window
(b) Goodput
Figure 8.23: H-TCP under asymmetric network conditions (250Mbit/sec capacity,
with Flow 1 experiencing 162ms RTT and Flow 2 experiencing 22ms RTT,
queuesize 20% BDP of 22ms).
4000
3500
3000
BicTCP 1
BicTCP 2
250
200
BicTCP 1
BicTCP 2
cwnd (packets)
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2000
1500
1000
500
Goodput (mbit/sec)
150
100
50
0
100 150 200 250 300 350 400
Time (seconds)
0
100 150 200 250 300 350 400
Time (seconds)
(a) Congestion Window
(b) Goodput
Figure 8.24: BicTCP under asymmetric network conditions (250Mbit/sec capacity,
with Flow 1 experiencing 162ms RTT and Flow 2 experiencing 22ms RTT,
queuesize 20% BDP of 22ms).
more of the network resources which results in a higher throughput compared
to the longer latency flow. It can be seen that the first BicTCP flow
consumes almost all of the available throughput. H-TCP, however, is able
to maintain (almost) cwnd fairness, and as such the longer latency H-TCP
flow is still capable of a achieving a respectable proportion of the network
throughput.
The fairness between the New-TCP algorithms is shown in Figure 8.25.