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The Application Layer
- The focus of this unit has been on the services and protocols to enable transport of data from one machine to another machine.
- None of the services (at the transport layer and below) are directly accessed by users.
- Users access applications, and applications depend on services from transport layer and below.
- There are many protocols for the applications themselves:
- E-mail
- Net news and bulletin boards.
- The World Wide Web
- Multimedia
- But even above the transport layer, we have protocols which support applications – 3 example categories of these:
- Security
- Domain Name System
- Network Management
In the remaining time we have in this unit, we will have a look at the Security and DNS. We will leave the rest as optional reading for your own interests.
Just as a note, the workings of all of the application protocols above are covered in detail in the unit B211 Internet Computing, although in much less technical terms than in this unit.
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