Which of the following can cause latency?

• A. Transmission conversions
• B. Processing delays
• C. Network traffic congestion
• D. All of the above

Answer: (D)

Latency is the total time it takes for a packet to travel from the sender to the receiver, and it can be affected by several factors. Transmission-related delays come from the time needed to push all the bits of the packet onto the physical link; longer packets or slower links mean longer transmission times, which adds to latency. Processing delays occur at each hop when devices inspect headers, perform routing decisions, and possibly handle security or other processing tasks; these small but finite times accumulate as the packet traverses the network. Network traffic congestion increases the time packets spend waiting in queues at intermediate devices, especially when many packets contend for the same resources. Since each of these elements can lengthen the overall delivery time, all of the above can cause latency, making “all of the above” the best choice.