# 50.012 Lecture 5

## Performance of rdt3.0

rdt3.0 has the "correct" implementation. However, it is not performant.
For example, in a 1 Gbps link, with 15 ms propagation delay, sending an 8000-bit packet will take a transmission delay of:
$$
D_{\text {trans }}=\frac{L}{R}=\frac{8000 \text { bits }}{10^{9} \mathrm{bits} / \mathrm{sec}}=8 \mathrm{microsecs}
$$

Utilization of the sender (fraction of time that the sender is busy sending):
$$
U_{\text {sender }}=\frac{L / R}{R T T+L / R}=\frac{.008}{30.008}=0.00027\ secs
$$
If RTT = 30 msec, 1 KB packet every 30 msec: 33kB/sec throughput over 1 Gbps link.