Correct Answer - Option 3 : 500 milliseconds, 65535 x 214
RTT (Round trip time) is the length of time it takes for a signal to be sent plus the length of time it takes for an acknowledgement of that signal to be received.
Bandwidth delay product: It gives the maximum amount of data that can be transmitted by the sender at a given time before waiting for acknowledgement.
It is measured in terms of RTT × Bandwidth.
In TCP, sequence number is limited to 16 bits i.e. TCP allows scaling of windows when bandwidth delay product is greater than 65,535.
Here, it is given that bandwidth = 1048560 bits/sec
RTT = α ms
Maximum possible window size = β
Bandwidth delay product = 1048560 × ∝
65535 B = 1048560 × α
α = 500 milliseconds
When we do scaling, window size increases from 64KB to 1 GB i.e. from 216 B to 230 B.
A 14-bit shift count is used in TCP header.
i.e. from 65535 to 65535 × 214