A point to point channel is built to test the performance of vegas. The link bandwidth is 3Mbps, propagation delay is 50 ms, maxmium buffer length(100ms). Vegas[1] is the first protocol that takes delay to infer link congesion.
Three flows are involved in tests. And the simulation time lasts 300 seconds.
When all flows enter the link at the same time.
Bandwidth dynamic of each flow:
One way delay of each received packets in each flow:
Low transmission delay is achieved, but bandwidhth allocation fairness is not guaranteed.
When all flows enter the link at different time.
Bandwidth dynamic of each flow:
Transmission delay:
Vegas suffers from the “late-comer” effect， the third flows get the highest bandwidth. When flows enter the link at different time, the reason is that the vegas control law makes different flows have different base rtt.
When two flows share link with reno flow.
The third flow takes reno for rate control.
Bandwidth dynamic of each flow:
Transmission delay:
[1] TCP Vegas: End to End Congestion Avoidance on a Global Internet