Yeah, it's "time taken to transmit", not round trip time or even one-way end to end latency. It's useful if you want to know eg. the minimum extra latency being

Yeah, it's "time taken to transmit", not round trip time or even one-way end to end latency. It's useful if you want to know eg. the minimum extra latency being added to other network flows because your NIC is busy transmitting this packet for the next n microseconds.