|  |  | Summary

In this chapter, you learned about the functions of the application layer and the different processes that occur as data packets travel through this layer. More specifically, you learned that the a pplication layer:

- identifies and establishes the availability of intended communication partners
- synchronizes cooperating applications

- establishes agreement on procedures for error recovery

- controls data integrity

In addition, you learned that the application layer supports:

- direct and indirect network applications
- the domain name system
- Telnet, FTP and HTTP

Now that you have completed this chapter, you should have a firm understanding of how the application layer provides services from the host to the destination.