This is a glossary of terms that have been used in CSCI 253. Each student should be familiar with these terms

 

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

- A -

Application layer: the seventh layer of the OSI model. It is the interface to the user, or application program.

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- B -

Byte: eight bits

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- C -

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- D -

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- E -

Encryption algorithm: a computation that transforms an entity into an unrecognizable form as directed by a controlling value (key). Its resistance to a brute force attack measures the strength of the algorithm; generally, the strength is directly proportional to the width of the key.

ES: End System - the entity in a communications network that originates information, or is the final destination of information. An end system supports applications or services used by end users (or just users).

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- F -

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- G -

 

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- H -

Hash function: a computation that maps a entity into a numeric value. The strength of a hash function is measured by the inability to find two entities that map to the same value.

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- I -

internet: (note lower case i) a collection of communications networks that are connected by bridges and/or routers. An internet uses TCP/IP as its protocol stack.

Internet: (note upper case I) the worldwide collection of communications networks (thousands of networks and end systems). The Internet is based upon the TCP/IP protocol stack.

IS: Intermediate System - the entity in a network that interconnect communications networks. The IS allows end systems is different networks communicate. An IS performs network routing functions and generally processes NPDUs.

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- J -

 

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- K -

 

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- L -

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- M -

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- N -

Network layer: layer three of the OSI model. This protocol layer is responsible for the routing of data through a communication network.

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- O -

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- P -

Presentation layer: layer six of the OSI model. This layer provides for the selection of a common syntax for representing data and for the transformation of application data into and from the common syntax.

Physical layer: layer one of the OSI model. This layer is concerned with the electrical, mechanical, and timing aspects of signal transmission over a physical media.

Propagation Time: Time it takes for a bit to traverse a link (move from source to destination).

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- Q -

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- R -

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- S -

Session layer: layer five of the OSI model. This layer manages a logical connection (session or dialog) between communicating processes or applications.

Sliding-window technique: a method of flow control in which a transmitting station may send numbered packets within a window of numbers. The window changes dynamically to allow additional packets to be sent.

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- T -

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- U -

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- V -

 

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- W -

 

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- X -

 

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- Y -

 

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- Z -

 

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This page was last updated on August 23, 2008