CertiGuide to Network+  9  Glossary

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Decompression

Returning a file to its original state. Refer to compression.

The process of making encrypted data readable again by converting ciphertext to plaintext.

A connection committed to a singular purpose. A fax machine with its one phone line has a dedicated line. A digital connection, such as a T-1 line is dedicated between two points.

A configuration item for the TCP/IP protocol that is the IP address of a directly reachable IP router. Configuring a default gateway creates a default route in the IP routing table.

The process of rewriting parts of a file to contiguous sectors on a hard disk to increase the speed of access and retrieval. When files are updated, the computer tends to save these updates on the largest continuous space on the hard disk, which is often on a different sector than the other parts of the file. When files are thus fragmented, the computer must search the hard disk each time the file is opened to find all of the parts of the file, which slows down response time. In Active Directory, defragmentation rearranges how the data is written in the directory database file to compact it.

When conceived by DARPA, TCP/IP was designed in a 4 layer model, pre-dating the OSI 7 layer model

Data Encryption Standard. A data encryption standard for converting non-classified data created in plain text to an encrypted form. DES typically operates on one of four modes.

CBC = Cipher Block Chaining

CFB = Cipher FeedBack

ECB = Electronic Cook Book

QFB = Output FeedBack

The on-screen work area in which windows, icons, menus, and dialog boxes appear.

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