Network Math: Bandwidth, Latency, Throughput & Transfer Time

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Convert the link speeds of Pinemoor Architects' offices from megabits per second into megabytes per second, gigabytes per hour and gibibytes per hour, and convert a file size from GiB to GB.
• Calculate how long five of Pinemoor's transfers take, how much fits in the 8-hour night window, and whether shipping disks beats the network for an 18,000 GiB archive.
• Calculate the speed of light in fibre, the one-way propagation delay and the minimum RTT for five routes from Pinemoor's Zurich office, and how much of the measured RTT is pure physics.
• Calculate the bandwidth-delay product of six Pinemoor paths, the throughput cap a 64 KB TCP window sets on each, the share of the link one connection can use, and what a scaled 4 MiB window achieves to Sydney.
• Estimate how much a little packet loss caps one TCP flow on six Pinemoor paths, how long the 48 GiB project copy then takes and how low the loss must be for 100 Mbps to New York.
• Work out how many payload bytes each packet carries in five scenarios (IPv4, IPv6, timestamps, VPN, jumbo frames), the efficiency on the wire, the goodput on a 1 Gbps link and the frame rate at line speed.
• Calculate the utilisation of the 50 Mbps line at Pinemoor's Lugano site office through the day, the average queueing delay and queue length it causes, and the highest traffic that keeps the queueing delay under 1 ms.
• Find the billable 95th percentile of Pinemoor's internet traffic from 5-minute samples, calculate the burstable bill, choose the port size for next year and chart the 95th-percentile trend.