Transmission Control Protocol (TCP) is a widely used transport protocol on the internet. TCP works as a connection-oriented protocol, which means it establishes a connection before data transmission and releases the connection after the data transfer is completed. TCP is a reliable protocol and ensures that the data sent from the sender is received at the receiver’s end without any errors. In this article, we will discuss how TCP designs how many packets can be sent per RTT from the sender to the receiver. RTT (Round Trip Time) is the time it takes for a packet to travel from the sender to the receiver and back to the sender. TCP uses RTT to calculate the number of packets that can be sent per RTT. TCP’s congestion control algorithm calculates the amount of data that can be sent per RTT and adjusts the sending rate accordingly. TCP’s congestion control algorithm is based on the concept of a congestion window (cwnd). The congestion window is the number of packets that can be sent without causing congestion on the network. TCP increases the cwnd by one packet every RTT until it detects congestion. When congestion is detected, the cwnd is reduced, and TCP switches to slow start mode. In slow start mode, the cwnd is doubled every RTT until the cwnd exceeds the previous congestion window. Once the cwnd exceeds the previous congestion window, TCP switches back to congestion avoidance mode. TCP designs how many packets can be sent per RTT by calculating the maximum segment size (MSS) and the round-trip time (RTT). The MSS is the largest amount of data that can be sent in a single TCP segment. The RTT is the time it takes for a packet to travel from the sender to the receiver and back to the sender. TCP calculates the maximum number of packets that can be sent per RTT by dividing the MSS by the RTT. In conclusion, TCP uses a congestion control algorithm to design how many packets can be sent per RTT from the sender to the receiver. TCP’s congestion control algorithm calculates the amount of data that can be sent per RTT and adjusts the sending rate accordingly. TCP calculates the maximum number of packets that can be sent per RTT by dividing the maximum segment size (MSS) by the round-trip time (RTT).