Video Description

Transport Layer- Session multiplexing

  • Flow control

  • Reliability

  • Segmentation

  • Uses TCP or UDP

  • Adds port number

  • Socket to socket

What is Port Number?- Service identifier

  • Length: 16 bits

  • Ranges from 0 to 65,535

  • Well-known ports: 0-1024

    • HTTP: 80

    • FTP: 21

    • DNS: 53

    • SMTP: 25

  • Ephemeral ports > 1024

UDP Protocol- Best-effort delivery (unreliable)

  • Provides applications with access to the network layer

  • Saves the overhead of reliability mechanisms

  • Connectionless protocol

  • Limited error checking

  • Data loss due to:

    • Routing error

    • Dupliation

  • No data-recovery features

TCP Protocol- Reliable protocol

  • Provides access to the network layer for applications

  • Connection-oriented protocol

  • Error checking

  • Data-recovery features

  • Sequencing of data packets

  • Acknowledgement of receipt

  • More commonly used than UDP

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