Bandwidth Delay Product determines the amount of data that can be transit into a network.
BDP=B.W*RTT
File to be sent: 1MB
RTT= 100ms
First case: BW= 1Mbps
BDP=10^6 * 100ms= 10,000bits=12500B
it means 12500 bytes are the maximum which can be Transit into the network. we have 1MB file, we can send maximum 12500 bytes in 1 RTT, hence we need
1MB/12500B=80 RTT to send entire file.it means in 1 RTT only 1.25% file is sent.
Second Case: BW=1 Gbps
BDP=10^9 * 100ms= 10^8bits=12500000 Bytes or 12.5 MB
it means 12.5 MB are the maximum bytes which can be Transit into the network.
Our file size is only 1MB, and maximum we can send in 1 RTT is 12.5 MB, hence we need only 1 RTT to send entire file, and 1MB is not even close to the BDP i.e 12.5 MB.
