Common Formulas in Computer Networks

This file is a collection of all important formulas discussed throughout the course.

This file will be updated as we cover new formulas.

Unit 1: Delay, Loss, and Throughput

Transmission Delay: The time to push a packet of length L (bits) onto a link with transmission rate R (bps). $$ d_{trans} = \frac{L}{R} $$
Propagation Delay: The time for a bit to travel across a link of distance d (meters) at propagation speed s (m/s). $$ d_{prop} = \frac{d}{s} $$
Total Nodal Delay: The total delay experienced at a single router or node. $$ d_{nodal} = d_{proc} + d_{queue} + d_{trans} + d_{prop} $$
End-to-End Throughput: The overall throughput for a path with N links is the minimum of all link rates (the bottleneck). $$ \text{Throughput} = \min(R_1, R_2, \dots, R_N) $$