List two causes of network latency (i.e. delay in sending data). For each of the causes you list, explain how the latency due to that cause is calculated.
Try an answer before revealing the guidance below.
Key Concepts
- Transmission delay
- Propagation delay
- Packet length
- Link rate
- Distance
- Propagation speed
Answer Approach
- Choose two delay components that have a direct formula.
- For each one, name the quantities it depends on.
- Keep “time to push bits onto the link” separate from “time for a bit to travel the link”.
Full Answer
Answer status: Verified against study notes. Revision notes, not an official marking scheme.
Transmission delay is the time needed to put all L bits of a packet onto a link of rate R bits/s: L/R seconds. Propagation delay is the time for the signal to travel distance D through a medium with propagation speed S: D/S seconds. (Queuing and processing delay also contribute but have no fixed formula.)
Transmission delay = L / RPropagation delay = D / SShortcuts: K concepts · A approach · F answer · R reviewed · B bookmark · ← / → previous / next