If a data packet switch has a queue of data packets waiting when a new packet reach. The new packet will be located on the whole queue and will have to wait while the switch forward the previous packets.
Delay and throughput are not completely dependent. As traffic in a computer network raise, delays raise a network that performs at close to 100% of its throughput capacity experiences severe time delay.
DELAY THROUPUT PRODUCT:
It is calculated as delay time multiplied by effective throughput. It calculates amount of data that can be represent in the network. In fast network with long delay times, sender can generate big amounts of data before receiver receives first bit.