This glossary was written and prepared by Blair Bergum of  DNSnews.net
For additions or corrections to this glossary, please send email to glossary at dnsnews dot net

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CA

Certificate Authority, is issued by a server that issues encrypted digital certificates that contains the users public key and other identifiable information.

cable

a high-speed coaxial communications link to transmit data.

caching

is the process of saving in resident memory the information obtained through a name server query.

cache hit

the occurrence when a cache server returns an object directly from its storage memory.

cache miss

the occurrence when a cache server does not have the requested object in its storage memory.

cache poisoning

refers to what happens when there is misdirected Internet activities caused by alternate authoritative roots. The DNS assumes a single authoritative root, and when there are other “alternate” authoritative roots, these misdirected alternate-root resource records, can corrupt the cache of an authoritative root with erroneous information.

cache server

stores the local copies of webpages and images that have recently been requested. A cached webpage or image can be delivered to a client faster than can be achieved by a web server.

cache total requests

the summation of cache hits plus cache misses (cache hits + cache misses = cache total requests).

CAIDA

Cooperative Association for Internet Data Analysis, provides tools and analyses which promote the engineering and maintenance for a robust and scalable internet infrastructure. CAIDA also provides research tools to members for the analysis of the DNS root and gTLD nameserver system.

canonical Name

Is the formal name for a CNAME, an original domain name that maps to an alias record or alias domain name. The CNAMES appear to the right of the Resource Records and is in the RDATA section of the Records. Note: the CNAME is not an alias, it merely maps to the alias name. See also CNAME.

capacity

1) number of connections or communication lines.

2) measure of the amount of bandwidth that can be transmitted.

capacity/load ratio

the ratio between the capacity and load, where a web hosting service should maintain the load at (1/3), one third of capacity load ratio in order to have a stable pipe.

ccNSO

Country Code Name Supporting Organization, is the advisory body to ICANN concerning policy issues of the DNS as it relates to the Country Code TLD’s. http://www.ccnso.icann.org This organization is being created as of January of 2003. The DNSO was the former organization, which is now renamed the GNSO which now only manages the generic TLD’s.

CDN

Content Delivery Networks, are network servers placed geographically between the client and the webserver that serves up images and content faster than your own webserver can do. A CDN can deliver images and streaming data to lessen the bandwidth usages of a webserver and provide faster downloads due to its geographic positioning to the client. The CDN uses a distributed server cache system utilizing a CDN controller and edge servers. It uses the DNS to send requests to the edge servers so the edge servers can deliver the content (objects and images) to the client's browser.

CDN centralized model

specifies the placement of a smaller number of centralized edge servers that have a grater capacity of cache than those of the CDN distributed models. This model works best for low to medium-traffic volume websites.

CDN distributed model

specifies the placement of edge servers throughout the Internet's routing tables. This model works best for high-traffic volume websites.

cTLD

a term coined by the author of this glossary for country TLD, a short abbreviation for what is formerly known as ccTLD.  cTLD is used to follow the convention of a single character proceeding TLD to act as a descriptor.  (i.e. gTLD, uTLD, sTLD, rTLD)

ccTLD

county code TLD, refers to Top-Level-Domain extensions that utilize individual country codes, which are two letter designated codes that identify specific countries, such as .ca for Canada, and .tv for Tevula.

CENTR

Council of European National Top Level Domain Registries.

CERN

Counseil Europeen pour la Recherché Nucleaire (European Center for Particle Physics) is the organization in Geneva, Switzerland, that developed the software protocols and conventions in 1991 that formed the basis of what the World Wide Web is today.

CERT

1) Computer Emergency Response Team, is the response team of governments or organizations that handle security risks.

2) A registered service mark with the USPTO, of Carnegie Mellon University. CERT in this context is not to be expanded into an acronym. It was the first computer security incident response team formed by the SEI by DARPA in 1988. See also CERT/CC.

CERT/CC

CERT Coordination Center, is the Coordination Center for the computer security incident response team in the U.S. It is managed by the NSS (Networked System Survivability) Program which reports to the Director of the SEI (Software Engineering Institute).

CGI

Common Gateway Interface, is the standard for interfacing external applications with web servers. CGI’s are program scripts that are embedded inside of a webpage and invoked at the client in a browser.

CH

Chaos System class, refers to the class in the Resource Records identifying it as the Chaos System.

Chaos net

a class or set of internet protocols. Originally, an old network of historical significance.

CIC

Committee on Information and Communication, is a committee within the U.S. cabinet council that facilitates the coordination of policies that concern science and technology.

CIDR

Classless Inter-Domain Routing, was developed to do away with the old class A, B, C, network designators. Utilizing CIDR, a single IP address can be used to denote several unique IP addresses. The format for a CIDR IP address is the dotted quad of a conventional IP address followed by a slash and a number. e.g. 126.126.126.126/12 The number following the slash is referred to as an IP prefix. CIDR is also known as "supernetting".

CIFS

Common Internet File System, is a proposed protocol that allows application programs to make requests for files or services from other hosts connected to the Internet.

CIO

Chief Information Officer.

CISE

Computer and Information Science and Engineering, is a group within the NSF.

CISRTs

Computer Security Incident Response Teams.

class

identifies a 16 bit value that identifies a protocol for the Resource Records. See also class tags. Some classes are the following:

IN Internet System

CH Chaos System

CS CSNET &bnsp;  (obsolete)

HS Hesiod System

class A network

a class of network that can accommodate up to 16 million hosts.

class B network

a class of network that can accommodate up to 65,000 hosts.

class C network

a class of network that can accommodate up to 256 hosts, also referred to having exactly 256 addresses from .0 to .255, often expressed as 0/24 or a “/24”.

Classless Inter-Domain Routing

See CIDR.

class tags

the DNS requires this tag on every resource record. All approved TLD’s use the class “IN” on their resource records.

client

1) a computer or host that is connected to a network, that requests services from a server or another workstation connected to the network.

2) is the user who accesses or requests services via the Internet from another application that resides across a network.

3)An application that runs on a host and is dependent upon a server to perform some additional functions.

clustered shared servers

the technology where each website is replicated and runs on at least two servers. If one of the servers goes down, the website continues to operate, due to the server redundancy.

clustering

is the method of connecting two or more computers or nodes together so they act like a single computer. This is primarily done to achieve parallel processing, load balancing, and fault tolerance.

CMSA/CD

Carrier Sense Multiple Access/ Collision Detection, is an Ethernet technology that enables devices to sense when a collision of packets has occurred and waits a specified amount of time before resending the packets.

CMT

Community Trademark, simplifies the trademark registration process for members of the European Union.

CMU

Carnegie Mellon University

CNAME

short abbreviation for canonical name. A CNAME an alias record to a canonical "original" domain name. A CNAME is similar to performing the function of a character string substitution, where the alias name is substituted for the original when the DNS querying is performed. See also canonical name

CNRI

Corporation for National Research Incentives, is a non-profit organization founded in 198x, responsible for planning and implementing national research incentives that involve network based technologies. http://merlin.cnri.reston.va.us

cold standby

refers to when there is a standby server or database server offline, that can be brought online in a moments notice, should the primary server fail.

colocation

is when a client sends a server he owns to a host to be connected to the Internet backbone and is charged for bandwidth and connection services.  Also written as co-location.

Common Internet File System

see CIFS.

concurrent version system

see CVS.

CORE

Internet Council of Registrars, is a not-for-profit consortium of new private registrars formed as a draft plan issued by IAHC. CORE operates a shared registry for Internet domain names allowing registrars to access and maintain the registry records in real time. http://www.corenic.org and http://www.gltd-mou.org

country code

a two letter code that designates countries and nations according to the ISO 3166. The country code is a TLD and is controlled by the respective countries it is assigned to represent. Also referred to as cc for short. See also ccTLD.

CRYPT-PW

Cryptography Password, is one of the Guardian Authentication processes that can be used for identifying registrants of domain names so the authorized owner can make changes or modifications to their domain name.

CS

CSNET System, is a programming code for the CS class in the DNS Resource Records.

CSS

Cascading Style Sheets, a method in dynamic HTML to assign style attributes to a webpage.

CVS

Concurrent Version System, an open source revision control system for identifying specific revisions during development of a website. The changes are stored in a tree like file structure.

connection

a type of protocol as in TCP where packets of data are sent over a network and that the receiving end checks to ensure that all of the packets are received and reassembled.

connectionless

a type of protocol that does not have the receiving end reassemble the data once it arrives.

cyberspace

originally coined in 1984 by science fiction writer William Gibson. It now refers to the space between your computer and the server of network one is connecting. it is a portion of the Internet probably most closely similar to the Information Super Highway.

cybersquatter

a name given to individuals or organizations who register many TLD’s with the intention to only sell them back to the rightful trademark holder for a profit. In 1999 the U.S. Congress passed the Anti-Cybersquatting Consumer Protection Act (ACPA) and the U.S. House of Representatives passed the Trademark Cyberpiracy Prevention Act (TCPA) to make cybersquatting a crime.