멩굴굴's blog

applications

A complete software program designed for end users

어플리케이션 이란 것은 운영체제를 제한 나머지 프로그램으로 컴퓨터를 부릴 수 있는 소프트웨어를 총칭

authentication

A process whereupon a person must prove that they are legitimate users of that certain resource.

사람이 어떤 수단의 정당한 사용자 인 것을 확인해야 하는 과정.

bandwidth

The amount of data that can be transmitted in a certain amount of time For digital bandwidth, it is usually expressed in bits per second (bps). For analog bandwidth, it is expressed in cycles per second, or Hertz (Hz)

대폭 또는 띠폭이라고도 한다. 전기신호의 점유(占有)대역폭과 기기(

機器)의 전송(傳送)대역폭이 있다. 보통 전기신호는 복수인 주파수를 포함하고 있는데, 신호점유 대역폭이란 이 신호 중 99%의 전력을 포함하고 전전력(全電力)의 적어도 0.25%에 해당하는 서로 다른 모든 주파수를 포함하는 주파수대의 폭을 말한다. 또, 수신기 및 증폭기에서 수신 또는 증폭되는 주파수대의 폭을 이 수신기 또는 증폭기의 전송대역폭이라고 한다.

binary

A numbering system characterized by ones and zeros (1 = on, 0 = off)

이진법(二進法, binary)은 두 개의 숫자만을 이용하는 수 체계이다. 관습적으로 0과 1의 기호를 쓰며 이들로 이루어진 수를 이진수라고 한다. 이 이진법은 라이프니츠가 발명하였다

bits

A bit is a binary digit, taking a value of either 0 or 1. Binary digits are units of information storage and communication in computing.

비트(bit, binary digit)는 전산학과 정보 이론의 정보 단위이며, 두값이라고도 부른다. 이 분야에서 쓰이고 있는 최소의 정보저장 단위이며, 현재는 이를 대신할 지도 모르는 큐비트(qubit)에 대한 연구가 진척중이다. 하나의 비트는 0이나 1의 값을 갖을 수 있고, 각각은 참, 거짓 혹은 서로 배타적인 상태를 나타낸다

blog

A website where entries are made in journal style. Short for weblog is blog. A blog is created by the user and can make changes to the blog via templates or by altering the HTML code of the blog itself. Visitors can leave posts to the blog.

웹(web) 로그(log)의 줄임말로, 1997년 미국에서 처음 등장하였다. 새로 올리는 글이 맨 위로 올라가는 일지(日誌) 형식으로 되어 있어 이런 이름이 붙었다. 일반인들이 자신의 관심사에 따라 일기·칼럼·기사 등을 자유롭게 올릴 수 있을 뿐 아니라, 개인출판·개인방송·커뮤니티까지 다양한 형태를 취하는 일종의 1인 미디어이다.

broadcast

A form of transsmission whereupon on device transmits to all divices within the network or on another network.

checksum

A form of redundancy check, a simple way to protect the integrity of data by detecting errors in data that are sent through space (telecommunications) or time (storage). It works by adding up the basic components of a message, typically the asserted bits, and storing the resulting value. Anyone can later perform the same operation on the data. compare the result to the authentic checksum. and (assuming that the sums match) conclude that the message was probably not corrupted.

수신자가 같은 수의 비트가 도착했는지를 확인 할 수 있도록 전송단위 내의 비트 수를 세는것이다.

cloud

This symbol is used to represent network communications without showing specific details of the network architecture. The cloud typically is used to hide the details of layer 1 and layer 2.

coaxial

Components that share a common axis. In the case of Coaxial cable there are three different layers of material surrounding the inner conducting material. The outer conductor, the insulator and the protective outer jacket.

code

A set of symbols for communicating information or instructions.

collaboration tool

Something that helps people work together on a particular file or piece of software. Many people use the term collaboration tool in a software context, for instance, collaboration software such as google docs, Microsoft sharepoint server.

computer virus

A computer program that can copy itself and infect a computer without permission or knowledge of the user.

congestion

The state of a network when there is not sufficient bandwidth to support the amount of network traffic

converge

When different intermediary devices exchange information in ofrder to have a consistent viewpoint of the network. We can also use another form of the root word converge in the phrase "converged network". This kind of network aggregates various forms of traffic such as voice, video and data on the same network infrastructure.

converged network

A network that allows for voice, video and data to use the same IP network.

data networks

Digital networks used to send data between computers.

denial of service (DoS)

An attempt to make a computer resource unavailable to its intended user. Also called DoS.

device

Equipment that works in a network, eg. a omputer, a bridge, a switch, or a router, etc.

digital signatures

A type of asymmetric cryptography used to simulate the security properties of a signature in digital form rather than written form.

download

Transferring date (usually a file) form another computer to the computer you are using.

e-mail

Electronic mail (abbreviated "e-mail" or, often, "email") is a store and forward method of composing, sending, storing, and receiving messages over electronic communication systems.

end-to-end

End user device to end user device.

extranets

Part of a company's intranet that is extended to users outside the company (e.g : normally over the internet)

firewall

A hardware device or a software application designed to protect network devices from outside network users and/or malicious applications and files.

flow

Stream of data traveling between two endpoints across a network (for example, from one LAN station to another). Multiple flows can be transmitted on a single circuit.

hardware

Hardware are physical components of a computer, such as the hard drive, memory chip, motherboard, CPU, etc.

hashing algorithms

Reproducible method of turning some kind of data into a (relatively) small number that may serve as a digital "fingerprint" of the data. The algorithm "chops and mixes" (i.e., substitutes or transposes) the data to create such fingerprints, called hash values.

Hierarchical

Something that is classified according to various criteria into successive levels or layers. For instance, You can plan your network addressing in hierarchical way in order to provide for efficient routing.

hop

The passage of a data packet between two network nodes (for example, between two routers.)

Hypertext Transfer Protocol (HTTP)

A method used to transfer or convey information on the World Wide Web. It's original purpose was to provide a way to publish and relrieve HTML pages.

instant messaging (IM)

Real-time communication between two or more people via text or other data.

Internet

The Internet is a publicly accessible network of interconnected computer networks that trnsmit data by using IP, the internet protocol.

Internet Protocol (IP)

Network layer protocol in the TCP/IP stack offering a connectionless, best-effort (unreliable) internetwork service. IP provides features for addressing, type-of-service specificaion, fragmentation and reassembly, and security. Documented in RFC 791.

internetwork

The interconnection of two or more different networks.

Internetwork Operating System (IOS)

This is the operating system that many Cisco Systems network devices use Different versions of IOS have different functions for different devices.

intranet

A system internal to an organization such as a web site that is explicitly used by internal employees or students. Can be accessed internally or remotely.

Local Area Network (LAN)

The term Local Area Network (LAN) refers to a local network, or a group of interconnected local networks that are under the same adminstrative control. In the early days of networking, LANs were defined as small networks that existed in a single physical location. While LANs can be a single local network installed in a home or small office, the definition of LAN has evolved to include interconnected local networks consisting of many hundreds of hosts, installed in multiple buildings and locations.

media

In the context of this course media is the plural form of medium.

medium

A physical material in which data is transferred. For example, UTP is a form of networking media.

network

Multiple computers connected together using a communications system. The purpose of a network is for computers to communicatate and share files.

packet

Logical grouping of information that includes a header containing control information and (usually) user data. Packets are most often used to refer to network layer units of data. The terms datagram, frame, message, and segment are also used to describe logical information groupings at various layers of the OSI reference model and in various technology circles.

packet tracer

An instructional tool and network simulator developed by Cisco Systems to design, configure, troubleshoot, and visualize network traffic within a controlled, simulated program environment.

peer

A host or node that participates in some form of groupt. For instance peer-to-peer technology defines a group of peers that participate jointly in the same activity, each one have a server and client component.

peer-to-peer (p2p)

Peer to peer networking whereupon computers that are part of the same network create a distributed system. Mostly used to share files with other p2p peers. Peer-topeer computing calls for each network device to run both client and server portions of an application.

Personal Digital Assistant (PDA)

A hand-held device normally used to help keep a person organized.

podcast

Podcast is a collection of digital media files that are distributed over the Internet using syndication feeds, for palyback on protable media players and personal computers.

points of failure

Describes any part of the system that can, if it fails, cause an interruption of required service.

ports

process

A series of progressive and interdependent steps by which an end is attained.

protocol

A set of rules governing communication

Quality of Service (QoS)

QoS (Quality of Service) is a control mechanism that can provide different priority to different users or data flows, or guarantee a certain level of performance to a data flow in accordance with requests from the application program.

real-time

Events or signals that show output as fast as possible, or as they happen.

router

Network layer device that uses one or more metrics to determine the optimal path along which network traffic should be forwarded. Routers forward packets from one network to another based on network layer information.

routing

Process of finding a path to a destination host. Routing is very complex in large networks because of the many potential intermediate destinations a packet might traverse before reaching its destinaton host.

server

A computer that provides services to clients. Servers are the central point in client/server model networks. There exist many services that a server can provide to network clients. For example; DNS, DHCP, File storage, Application hosting, web site hosting.

software

Program or codes used by computer to carry out certain functions.

source

The origin of a message.

standard

An internationally recognized definition of technical specifications that ensure worldwide consistency.

stream

The continuous transmission of data from one location to another. For example a streaming video is a continuous, real-time flow of the video being downloaded as you watch the video.

switch

1) A network device that filters forwards and floods frames based on the destination address of each frame. The switch operates at the data link layer of the Open System Interconnection (OSI) model.

2) A general term applied to an electronic or mechanical device that allows a connection to be established as necessary and terminated when there is no longer a session to support.

Transmission Control Protocol (TCP)

The transport layer protocol used as the basis of most Internet services. It is used in conjunction with the Internet Protocol (IP). It provides reliable, connection-oriented communication, ensuring that packets reach their intended destinations.

Transmission Control Protocol/Internet Protocol (TCP/IP)

Common name for the shuite of protocols developed by the U.S. DoD in the 1970s to support the construction of worldwide internetworks. TCP and IP are the two best-known protocols in the suite.

unshielded twisted pair (UTP)

UTP is a four twisted-pair wire medium used in a variety of networks. UTP does not require the fixed spacing between connections that is necessary with coaxial-type connections. There are five types of UTP cabling commonly used: Category 1 cabling, Category 2 cabling, Category 3 cabling, Category 4 cabling, and Category 5 cabling,

Voice over IP (VoIP)

Voice data encapsulated in an IP packet allow it to traverse already implemented IP networks without needing its own network infrastructure.

weblogs

A website where entries are made in journal style. Short for weblog is blog. A blog is created by the user and can make changes to the blog via templates or by altering the HTML code of the blog itself. Visitors can leave posts to the blog.

Wide Area Network (WAN)

A network that spans broader geographical area than a Local Area Network, over public communications networks.

wiki

A website that lets visitors add, edit and delete content, typically without the need for registration. A good example of this is a site called wikipedia where visitors can access the website and add their commentaries to already written articles or create a new article.

wireless technology

Technology that allows for communication without needing physical connectivity. Examples of wireless technology cellular telephones, personal digital assistants (PDA's), Wireless access points and wireless NICs.

Wrold wide web (WWW)

A system of interlinked, hypertext documents accessed via the Internet. Entry into the World Wide Web requires a program called a browser such as Internet Explorer or Netscape and connectivity through an internet service provider (ISP). With a web browser, a user views web pages that may contain text, images, videos, and otehr multimedia and navigates between them using hyperlinks.

**cheapter 2

channel

The medium used to transport information from a sender to a receiver.

client

A computer system that accesses a service on another computer remotely by accessing the network.

datagrams

A data packet that traverses an IP based network.

decapsulation

The process of removing encapsulations in a receiving device. As PDUs arrive on each layer of the OSI model by the receiving computer the system discards of the previous layer's PDU in order to analyze its current layer's respective PDU.

default gateway

A device on a network that serves as an access point to another network. A default gateway is used by a host when an IP packet's destination address belongs to someplace outside the local subnet. A router is a good example of a default gateway.

e-mail client

Program used to download and send email Email clients use pop3 to receive emails and use SMTP to send emails.

encapsulation

The wrapping of data in a particular protocol header.

encoding

The process of transforming data form one form to another form. Line encoding is the process by which information from a source is converted into symbols to be communicated.

end devices

A device such as a desktop or mobile, device that is used by an end user.

error recovery

A procedure that allows a user to recover from errors such as failure of either host system or transfer process.