As far as I know:
(1) Latency (τ) = transmission delay + propagation delay + queuing delay + processing delay
(2) Round-trip time (RTT) is two times the latency (assuming the same latency both ways)
However, while I was reading about slot time, I found the standard 802.3 says:
The slot time shall be larger than the sum of the Physical Layer
round-trip propagation time and the Media Access Layer maximum jam.
Is this round-trip propagation time the same as RTT? If so, why add "propagation"? RTT includes other times beside propagation, that would be misleading.
Best Answer
Context is everything.
Your definition of latency is a generic definition.
RTT is usually defined in the context of IP networking. Since a remote host is assumed not to be under your control, all the components of the delay are lumped together.
802.3 is a LAN standard, where all the devices are under your control. In this context, they are talking about the characteristics of the particular media.
In essence, different people may use different terminology to describe the same thing.
You will find that a lot of networking terms are not precisely defined as you might expect.