How is the RTT defined by the use of a "simple" ping command?
Example (Win7):
ping -l 600 www.google.de
My understanding is: There will be send a ICMP message to google with the size of 600 bytes (request). Google copies that message (600 bytes) and sends it back to the destination (reply). The RTT is the (latency) time for the whole procedure involving the sending and the getting of the 600 byte message.
Is that right?
Latency is typically caused by mainly two reasons:
1) Distance between two Nodes; This plays a vital role in calculating latency. For example, consider a scenario where Node A and Node B need to communicate, sending ICMP messages to each other and vice-versa. a) The fewer the number of hops, the lower the latency will be. More hops, more latency. Solution: You can select an alternate path for the communication, maybe the path having less distance.
2) How busy the network is; Whenever packet is sent from one network to other, routers process the packets, which in turn takes some milliseconds doing so. It will add up all the time taken to and fro for calculating the latency. a) It depends upon the process device, how busy it is. If less busy, packets will be processed and forwarded faster, if busy it will take time. Solution: one possible solution can be using QOS where in you can prioritize the traffic, not ICMP traffic of course, some other kind of traffic.