OSI for CCNA Layer 4: Transport - dummies

By Silviu Angelescu

Part of CCNA All-in-One Certification For Dummies Cheat Sheet

On the CCNA exam, you’ll work with hosts. The transport layer manages the transport of data between two hosts communicating over a network. In a nutshell, the transport layer does the following:

  • Slices up the data to be transmitted into small chunks called data segments that can be easily sent over the network medium.

  • Reassembles the data in order on the receiving host:

    • Some transport protocols send the segments in order.

    • Other protocols, such as Transmission Control Protocol (TCP), send the data segments in any order and reassemble them in the correct order on the receiving host.

  • Provides some error-detection mechanisms.