Which Quality of Service (QoS) parameter indicates variation in network delay?

The parameter that indicates variation in network delay is jitter. Jitter refers to the variability in time delay in packet delivery over a network. It measures how much the delay of received packets fluctuates, which can significantly impact applications requiring real-time communication, such as voice over IP (VoIP) and online gaming. When jitter is low, packets are received consistently at regular intervals; high jitter can lead to packets arriving out of order, causing disruptions in the communication stream.

Latency, on the other hand, represents the total time it takes for a packet to travel from the source to the destination, not the variation in that time. Bandwidth refers to the maximum data transfer capacity of a network link, while throughput measures the actual amount of data successfully transmitted over a network in a given time frame. Neither bandwidth nor throughput conveys information about changes in delay, making jitter the correct choice for understanding variations in network delay.