VIN VIN Technologies › Labs › Traffic and performance
TCP and UDP share a bottleneck
Traffic and performance · free online experiment, runs in your browser with no install or sign-up.
Open this experiment in the network simulator
Objective
A bulk TCP transfer and a 6 Mbit/s UDP stream compete for an 8 Mbit/s link.
Procedure
- Run and read the Summary tab: UDP loss, TCP goodput, retransmissions.
- Select the bottleneck link and raise its rate to 20 Mbit/s: both flows run unhindered.
- Increase the queue length: more delay, fewer drops.
Theory
Queues fill, packets are dropped, TCP's congestion window shrinks. UDP does not back off, so it keeps its rate and TCP gets what remains.
Network blocks used
4 × Host / PC, Router, 2 × Switch
Open this experiment in the network simulator