End-to-End Delay

End-to-end delay is the total time it takes for a data packet to travel from the source to the destination across a network.  This delay encompasses all the individual delays that occur as the packet is transmitted, propagated, and processed along the route.  End-to-end delay is made up of several components:

• Processing Delay  -  The time taken by routers and switches to process the packet header, perform routing decisions, and handle error checking.
• Transmission Delay  -  The time taken to push all the packet's bits onto the transmission medium (dependent on the packet size and the transmission rate).
• Propagation Delay  -  The time taken for a signal to propagate across the physical medium between devices (based on distance and speed of signal propagation).

The sum of these delays gives the total end-to-end delay, which is an important performance metric in network communication, especially for real-time applications like voice and video calls, where lower delay is crucial for a good user experience.

 

End-to-end Delay formula
\( D_{ete} \;=\;  n \; (D_{prop} + D_{tran} + D_{proc} )\)     (End-to-end Delay) \( n \;=\;  D_{ete} \;/\; D_{prop} + D_{tran} + D_{proc} \) \( D_{prop} \;=\;  ( D_{ete} \;/\; n ) - D_{tran} - D_{proc} \) \( D_{tran} \;=\;  ( D_{ete} \;/\; n ) - D_{prop} - D_{proc} \) \( D_{proc} \;=\;  ( D_{ete} \;/\; n ) - D_{prop} - D_{tran} \)
Symbol	English	Metric
\( D_{ete} \) = End-to-end Delay	-	\(ms\)
\( n \) = Number of Links between Routers	-	\(dimensionless\)
\( D_{prop} \) = Propagation Delay	-	\(ms\)
\( D_{tran} \) = Transmission Delay	-	\(ms\)
\( D_{proc} \) = Processing Delay	-	\(ms\)