Delay component of the round trip time contains sum of: 1. delays in buffer queue 2. serialization delays 3. processing delays 4. propagation delays While propa

Delay component of the round trip time contains sum of: 1. delays in buffer queue 2. serialization delays 3. processing delays 4. propagation delays While propagation delay usually makes up the largest portion, it is not always the case. Furthermore, the routing efficiency varies widely, depending on IX peering and INET upstream arrangements of your ISP. It also helps to know the topology of the underlying physical networks, or at least major POPs. This is like measuring intensity of the Sun with the naked eye.