NetworkingLesson 7Free preview

CS Network Transport

This lesson is part of Cyber Security · All levels

Summary

The transport layer (layer 4 OSI) is responsible for end-to-end data transmission between hosts, including flow control and reliability of delivery. The two main protocols are connection-oriented and reliable TCP, and lightweight UDP without guarantee of delivery. Each service uses a specific port number as a logical gateway.

Key points

TCP reliable with a three-way handshake mechanism; UDP fast without guarantee.
The port is the logical number 0-65535 as the service identity.
Common ports: 22 (SSH), 80 (HTTP), 443 (HTTPS), 53 (DNS) and the following:
TCP flow control and error recovery make it suitable for web and email.
UDP is chosen for streaming, VoIP, and DNS that prioritize speed.

Full lesson

Code examples and quizzes

Full lessons, code examples, and quizzes are available to subscribers. 5 questions.