Session and Presentation Layers Honolulu Community College Cisco Academy Training Center Semester 1 Version 2.1.1

Session Layer Functions This includes starting, stopping, and re- synchronizing sessions (dialogue separation).

Modes of Communication Two-way alternate communication is where two parties take turns sending messages to avoid interrupting each other. Another solution is that each person would type or talk whenever he/she wishes, regardless of who is transmitting/talking, and you would assume that more information is always on the way - this is referred to as two-way simultaneous communication. Determining which role to play is called dialogue control.

Session Layer Protocols

Presentation Layer Functions

Three Main Functions  Data formatting Extended Binary Coded Decimal Interchange Code (EBCDIC) or American Standard Code for Information Interchange (ASCII) or Unicode is used to represent characters onscreen. The presentation layer provides translation between these codes.  Data encryption  Data compression

Other Presentation Layer Formats

HTML This format acts as a set of directions that tell a Web browser how to display and manage documents. Hypertext Markup Language is the language of the Internet. HTML directions tell a browser whether to display text, or to hyperlink to another URL (Uniform Resource Locator). HTML is not a programming language, but is a set of directions for displaying a page.

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