dnodalโ is the sum of:
dprocessingโ is the time checking for bit errors. Typically finishes in milliseconds.
dqueueingย delayโ is the time waiting in the memory if the router is busy transmitting something else.
dtransmissionย delayโ=bandwidthpacketย sizeโ
dpropagationย delayโ=ccableย lengthโ is the physical constraint of propagation. c is the speed of connection, usually the speed of light.
Propagation Delay