Latency and jitter: which statement best defines them?

• A. Jitter is variation in delay; latency is the total end-to-end delay.
• B. Jitter is total end-to-end delay; latency is variation in delay.
• C. Jitter is throughput; latency is packet loss rate.
• D. Jitter is routing protocol; latency is security risk.

Answer: (A)

Latency is the total end-to-end delay for a packet to travel from sender to receiver, incorporating all factors like propagation, processing, and queuing. Jitter is the variation in that delay from packet to packet, showing how much the arrival times fluctuate.

So, if one packet takes a consistent 20 ms to arrive and the next also around 20 ms, jitter is low. If the delays vary—say 20 ms for one packet, 60 ms for the next—jitter is high. This variability is critical for real-time applications like voice and video, which rely on steady timing and may use jitter buffers to smooth out the differences.

Other options aren’t correct because jitter isn’t the overall delay and latency isn’t the amount of variation. Jitter isn’t about throughput, and it isn’t the packet loss rate. It also isn’t related to routing protocols or security risk.