Whether the Propagation delay contains the signal from chain into the cache queue? From the wikipedia: > Propagation delay – time for a signal to reach its destination and from the slideplayer.com I found the image:...--prophetes.ai

Whether the Propagation delay contains the signal from chain into the cache queue? From the wikipedia: > Propagation delay – time for a signal to reach its destination and from the slideplayer.com I found the image: ![enter image description here]( there seems the Propagation delay represent the signal transport on the chain and `into the other router`(whether this is mean `signal into the cache queue` contained in the propagation delay), there do not make it clear the whether the propagation delay contains the `signal into the cache queue`. So, I want to make it clear in this professional networking site.

The propagation delay does not include processing overhead like queueing/unqueueing. It's purely medium-in to medium-out. Neither egress nor ingress queueing, nor serialization ("transmission delay" in your diagram) is part of the propagation delay.