Round Trip Time (RTT)

What is RTT?

Round Trip Time is the elapsed time for a transmitted signal to traverse over the network to a remote host and back.

Why RTT?

RTT have direct effect over systems that have two-way interactive communication, (for example TCP) RTT determine the rate of which a TCP sender can send its packets therefor directly effecting the throughput. It is also common to use RTT for TIMEOUT.
When setting a large number for TIMEOUT there is a risk for low throughput (the client wait too long before retransmitting ), when setting the TIMEOUT too less there is a risk of unwanted retransmitions (a packet could still traversing in the link and the senders believes it was dropped). If a client can predict the right RTT in the network and use the number for TIMEOUT it can increase the throughput without unnessacry retransmitions .

What variables effect RTT?

There are verious of factors that effect the RTT :

• The data transfer rate of the source's Internet connection
• Transmission medium (copper, optical fiber or satellite)
• The physical distance between the source and the destination
• The number of other requests being handled by intermediate nodes and the remote server
• The speed with which intermediate nodes and the remote server function

Simulation

RTT simulation is a rough display of how verious factors effect RTT. select different transfer rate(10Mbps,100Mbps,100Mbps) , transmission medium(faber optic etc) and the delay of the nodes ( cause by proccessing time or busy network adapters).

The RTT in the simulstion is just a rough number and cannot be taken as a spec for any of the components.It is purely to display how verious components in the network can effect RTT and how some factors can cause lower latency in the network.