Which of the following is true with respect to the delay in datagram networks?

In datagram networks, several types of delays can occur as a packet travels from the source to the destination. These delays are inherent to packet-switched networks and are important to understand for network analysis and design. Here are the true aspects concerning delay in datagram networks:

1. Transmission Delay: This is the time required to push all the packet’s bits into the wire at the data rate of the link. Transmission delay is a function of the packet’s length and the transmission rate of the link, given by the formula (frac{text{Packet size (bits)}}{text{Transmission rate (bps)}}).

2. Propagation Delay: This is the time it takes for a bit to travel from the sender to the receiver, and it depends on the physical length of the path between two nodes and the propagation speed of the medium (which is close to the speed of light). The formula is (frac{text{Distance (m)}}{text{Propagation speed (m/s)}}).

3. Queueing Delay: Occurs at routing nodes when packets arrive and need to wait in queue before they can be processed and forwarded. Queueing delay varies dynamically with the network’s current traffic load and the packet’s position in the queue.

4. Processing Delay: The time required to examine the packet’s header and determine where to direct the packet is called processing delay. It may also include other factors such as error checking. Processing delay is typically much shorter than other