Computer Networks Simulations and Delay Calculators
Computer networking is easiest to understand when you can change the numbers and watch what happens. These simulations cover the topics every networks course asks about: the four components of nodal delay (transmission, propagation, processing and queuing), the difference between packet switching and circuit switching, how packets flow across routers, and how TCP controls congestion. Each one runs the real formula on your own inputs, explains every step and shows the calculation, so you can check homework answers and prepare for exams.
8 interactive simulations
Transmission Delay
How long a router needs to push every bit of a packet onto the link.
Open simulation →Propagation Delay
How long a signal takes to travel along the physical link.
Open simulation →Processing Delay
The time a router spends inspecting a packet and choosing its next hop.
Open simulation →Queuing Delay
Packets waiting in line for the outgoing link — and why traffic intensity matters.
Open simulation →Packet Switching
Split a message into packets and pipeline them across store-and-forward links.
Open simulation →Circuit Switching
Reserve a dedicated circuit first, then send — and compare with packet switching.
Open simulation →Data Transmission & Packet Flow
Follow packets across routers and see every part of the nodal delay.
Open simulation →Network Congestion
TCP's congestion window growing, overflowing the bottleneck and backing off.
Open simulation →Frequently asked questions
What are the four types of delay in computer networks?
Processing delay, queuing delay, transmission delay (L/R) and propagation delay (d/s). Their sum at every hop is the nodal delay, and the sum over all hops is the end-to-end delay.
Which networking topics can I practise here?
Delay calculations, store-and-forward packet switching with the (N+K−1)L/R formula, circuit switching with TDM, end-to-end packet flow and TCP Tahoe/Reno congestion control.
Are the answers accurate enough for exams?
The formulas are the standard textbook ones and the simulations are tested against textbook examples, but always follow your own course's conventions (for example whether kilo means 1,000 or 1,024).