TCP Window Scaling and Flow Control — Lesson 2

This lesson covers the concept of TCP window scaling and flow control, particularly in the context of satellite links with large Round Trip Time (RTT). It explains how the window size can be increased to improve throughput and how flow control is used to maximize capacity utilization. The lesson also discusses the impact of introducing a satellite link into the signal path, which increases RTT and affects throughput. It provides a detailed example of estimating TCP throughput with a specific RTT and TCP window size. The lesson further delves into the concept of flow control from both the transmitter and receiver's perspectives. It also introduces the Space Communication Protocol Standards-Transport Protocol (SCPS-TP) for space communication.

Video Highlights

00:20 - Introduction and example problem
02:21 - Flow control and its importance in maximizing capacity utilization
02:27 - Explanation of receiver side and transmitter side flow control
04:31 - How slow start and congestion avoidance phases work with an example
10:11 - Fast recovery and fast retransmit in TCP protocol
12:07 - Example problem
18:29 - Space Communication Protocol
21:29 - Error prone link and corruption induced loss

Key Takeaways

- TCP window scaling is used to increase window size and improve throughput, especially in satellite links with large RTT.
- Flow control is essential to maximize capacity utilization and can be controlled by both the transmitter and receiver.
- The introduction of a satellite link into the signal path increases RTT, which affects throughput.
- The Space Communication Protocol Standards-Transport Protocol (SCPS-TP) is a modification of the standard TCP for space-related use.