05.08.2014 Views

An Investigation into Transport Protocols and Data Transport ...

An Investigation into Transport Protocols and Data Transport ...

An Investigation into Transport Protocols and Data Transport ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

8.3. Results 181<br />

600<br />

500<br />

St<strong>and</strong>ard TCP<br />

BicTCP<br />

4500<br />

4000<br />

3500<br />

St<strong>and</strong>ard TCP<br />

BicTCP<br />

cwnd (packets)<br />

400<br />

300<br />

200<br />

cwnd (packets)<br />

3000<br />

2500<br />

2000<br />

1500<br />

100<br />

1000<br />

500<br />

0<br />

100 150 200 250 300<br />

Time (seconds)<br />

0<br />

100 150 200 250 300<br />

Time (seconds)<br />

(a) 22ms<br />

(b) 162ms<br />

Figure 8.37: St<strong>and</strong>ard TCP competing against BicTCP under asymmetric network<br />

conditions (250Mbit/sec capacity, 20% BDP queuesize).<br />

600<br />

500<br />

St<strong>and</strong>ard TCP<br />

HSTCP<br />

4500<br />

4000<br />

3500<br />

St<strong>and</strong>ard TCP<br />

HSTCP<br />

cwnd (packets)<br />

400<br />

300<br />

200<br />

cwnd (packets)<br />

3000<br />

2500<br />

2000<br />

1500<br />

100<br />

1000<br />

500<br />

0<br />

100 150 200 250 300<br />

Time (seconds)<br />

0<br />

100 150 200 250 300<br />

Time (seconds)<br />

(a) 22ms<br />

(b) 162ms<br />

Figure 8.38: St<strong>and</strong>ard TCP competing against HSTCP under asymmetric network<br />

conditions (250Mbit/sec capacity, 20% BDP queuesize).<br />

ments, the plateau has negligible effect <strong>and</strong> effectively becomes an aggressive<br />

linear increase causing unfairness against the St<strong>and</strong>ard TCP flow.<br />

The performance of HSTCP’s friendliness is shown in Figure 8.38. Compared<br />

to that of BicTCP (Figure 8.37), it is observed that the period between<br />

(synchronised) congestion events is less, therefore forcing St<strong>and</strong>ard TCP <strong>into</strong><br />

a slightly lower average cwnd causing less friendliness of HSTCP against<br />

St<strong>and</strong>ard TCP than that of BicTCP. At lower latencies, the opposite is true;<br />

HSTCP induces congestion less frequently <strong>and</strong> therefore is more fair against<br />

the St<strong>and</strong>ard TCP flow.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!