10. Transport Layer

session session session session session...  Provides best-effort delivery Has no data-recovery features  Provides limited error checking UDP Characteristics... TCP Characteristics Fu

Transport Layer

 Reliability (when required)

session session session session session

 Reliability (when required)

10 M

1480 1480 1480 1480 1480 1480

 Reliability (when required)

Flow Control

1000 M 100 M

Flow Control

Flow Control

 Reliability (when required)

 Reliability (when required)

ACK

Reliable vs Best-Effort Comparison

 Provides best-effort delivery

 Has no data-recovery features

 Provides limited error checking

UDP Characteristics

Data Encapsulation

Application 7

Presentation 6

Session 5

Transport 4

Network 3

Data Link 2

Header

UDP Header

Source Port

Data 80 1024 2.2.2.2 1.1.1.1 Data

Data 1024 1024 80 80 1.1.1.1 2.2.2.2

web server

raovat.com 3.3.3.3

Data 1025 21 10.0.0.1 10.0.0.2 Data 1026 69 10.0.0.1 10.0.0.2 Data 1027 80 10.0.0.1 10.0.0.2

TCP Characteristics

 Full-duplex mode operation

 Error checking

 Data-recovery features

TCP Header

Urgent Pointer

Urgent Pointer

– Domain Name System

TCP/IP Application Layer Overview

Mapping Layer 4 to Applications

Three-Way Handshake

Three-Way Handshake

SYN

ACK SYN

SEQ = 100 ACK = 101 SEQ = 300 ACK = 301

Three-Way Handshake

ACK = 101 SEQ = 300

TCP Acknowledgment

Fixed Windowing

TCP Sliding Windowing

TCP Sliding Windowing

segment 1

ACK 2 windown size = 1

windown size = 4

segment 9

windown size = 8

TCP Sequence and Acknowledgment Numbers