BOF: See: Birds Of a Feather
BOOTP: The Bootstrap Protocol, described in RFCs 951 and 1084, is used for booting diskless nodes. See also: Reverse Address Resolution Protocol
Border Gateway Protocol (BGP): The Border Gateway Protocol is an exterior gateway protocol defined in RFCs 1267 and 1268. It's design is based on experience gained with EGP, as defined in STD 18, RFC 904, and EGP usage in the NSFNET Backbone, as described in RFCs 1092 and 1093. See also: Exterior Gateway Protocol
bounce: The return of a piece of mail because of an error in its delivery. [Source: ZEN]
bridge: A device which forwards traffic between network segments based on datalink layer information. These segments would have a common network layer address. See also: gateway , router
broadband: A transmission medium capable of supporting a wide range of frequencies. It can carry multiple signals by dividing the total capacity of the medium into multiple, independent bandwidth channels, where each channel operates only on a specific range of frequencies. See also: baseband
broadcast: A special type of multicast packet which all nodes on the network are always willing to receive. See also: multicast
broadcast storm: An incorrect packet broadcast onto a network that causes multiple hosts to respond all at once, typically with equally incorrect packets which causes the storm to grow exponentially in severity.
brouter: A device which bridges some packets (i.e., forwards based on datalink layer information) and routes other packets (i.e., forwards based on network layer information). The bridge/route decision is based on configuration information. See also: bridge , router
BSD: See: Berkeley Software Distribution
BTW: By The Way
Bulletin Board System (BBS): A computer, and associated software, which typically provides electronic messaging services, archives of files, and any other services or activities of interest to the bulletin board system's operator. Although BBS's have traditionally been the domain of hobbyists, an increasing number of BBS's are connected directly to the Internet, and many BBS's are currently operated by government, educational, and research institutions. See also: Electronic Mail , Internet , Usenet [Source: NWNET]
Campus Wide Information System (CWIS): A CWIS makes information and services publicly available on campus via kiosks, and makes interactive computing available via kiosks, interactive computing systems and campus networks. Services routinely include directory information, calendars, bulletin boards, databases.
CCIRN: See: Coordinating Committee for Intercontinental Research Networks
CCITT: See: Comite Consultatif International de Telegraphique et Telephonique
CERT: See: Computer Emergency Response Team
checksum: A computed value which is dependent upon the contents of a packet. This value is sent along with the packet when it is transmitted. The receiving system computes a new checksum based upon the received data and compares this value with the one sent with the packet. If the two values are the same, the receiver has a high degree of confidence that the data was received correctly. [Source: NNSC]
circuit switching: A communications paradigm in which a dedicated communication path is established between two hosts, and on which all packets travel. The telephone system is an example of a circuit switched network. See also: connection-oriented , connectionless , packet switching
client: A computer system or process that requests a service of another computer system or process. A workstation requesting the contents of a file from a file server is a client of the file server. See also: client-server model , server [Source: NNSC]
client-server model: A common way to describe the paradigm of many network protocols. Examples include the name-server/name-resolver relationship in DNS and the file-server/file-client relationship in NFS. See also: client , server , Domain Name System , Network File System
CNI: See: Coalition for Networked Information
Coalition for Networked Information (CNI): A consortium formed by American Research Libraries, CAUSE, and EDUCOM to promote the creation of, and access to, information resources in networked environments in order to enrich scholarship and enhance intellectual productivity.
Comite Consultatif International de Telegraphique et Telephonique: (CCITT) This organization is part of the United National International Telecommunications Union (ITU) and is responsible for making technical recommendations about telephone and data communications systems. Every four years CCITT holds plenary sessions where they adopt new standards; the most recent was in 1992. [Source: NNSC]
Computer Emergency Response Team (CERT): The CERT was formed by DARPA in November 1988 in response to the needs exhibited during the Internet worm incident. The CERT charter is to work with the Internet community to facilitate its response to computer security events involving Internet hosts, to take proactive steps to raise the community's awareness of computer security issues, and to conduct research targeted at improving the security of existing systems. CERT products and services include 24-hour technical assistance for responding to computer security incidents, product vulnerability assistance, technical documents, and tutorials. In addition, the team maintains a number of mailing lists (including one for CERT Advisories), and provides an anonymous FTP server, at "cert.org", where security-related documents and tools are archived. The CERT may be reached by email at "cert@cert.org" and by telephone at +1-412-268-7090 (24-hour hotline). See also: Defense Advanced Research Projects Agency , worm
congestion: Congestion occurs when the offered load exceeds the capacity of a data communication path.
connection-oriented: The data communication method in which communication proceeds through three well-defined phases: connection establishment, data transfer, connection release. TCP is a connection-oriented protocol. See also: circuit switching , connectionless , packet switching , Transmission Control Protocol
connectionless: The data communication method in which communication occurs between hosts with no previous setup. Packets between two hosts may take different routes, as each is independent of the other. UDP is a connectionless protocol. See also: circuit switching , connection-oriented , packet switching , User Datagram Protocol
Coordinating Committee for Intercontinental Research Networks (CCIRN): A committee that includes the United States FNC and its counterparts in North America and Europe. Co-chaired by the executive directors of the FNC and the European Association of Research Networks (RARE), the CCIRN provides a forum for cooperative planning among the principal North American and European research networking bodies. See also: Federal Networking Council , RARE [Source: MALAMUD]
core gateway: Historically, one of a set of gateways (routers) operated by the Internet Network Operations Center at Bolt, Beranek and Newman (BBN). The core gateway system formed a central part of Internet routing in that all groups must advertise paths to their networks from a core gateway. [Source: MALAMUD]
Corporation for Research and Educational Networking (CREN): This organization was formed in October 1989, when Bitnet and CSNET (Computer + Science NETwork) were combined under one administrative authority. CSNET is no longer operational, but CREN still runs Bitnet. See also: Bitnet [Source: NNSC]
cracker: A cracker is an individual who attempts to access computer systems without authorization. These individuals are often malicious, as opposed to hackers, and have many means at their disposal for breaking into a system. See also: hacker , Computer Emergency Response Team , Trojan Horse , virus , worm
CRC: See: cyclic redundancy check
CREN: See: Corporation for Research and Educational Networking
CWIS: See: Campus Wide Information system
Cyberspace: A term coined by William Gibson in his fantasy novel Neuromancer to describe the "world" of computers, and the society that gathers around them. [Source: ZEN]
Cyclic Redundancy Check (CRC): A number derived from a set of data that will be transmitted. By recalculating the CRC at the remote end and comparing it to the value originally transmitted, the receiving node can detect some types of transmission errors. [Source: MALAMUD]
DARPA: See: Defense Advanced Research Projects Agency
Data Encryption Key (DEK): Used for the encryption of message text and for the computation of message integrity checks (signatures). See also: encryption
Data Encryption Standard (DES): A popular, standard encryption scheme. See also: encryption
datagram: A self-contained, independent entity of data carrying sufficient information to be routed from the source to the destination computer without reliance on earlier exchanges between this source and destination computer and the transporting network. See also: frame , packet [Source: J
DCA: See: Defense Information Systems Agency
DCE: Data Circuit-terminating Equipment
DCE: See: Distributed Computing Environment
DDN: See: Defense Data Network
DDN NIC: See: Defense Data Network Network Information Center
DECnet: A proprietary network protocol designed by Digital Equipment Corporation. The functionality of each Phase of the implementation, such as Phase IV and Phase V, is different.
default route: A routing table entry which is used to direct packets addressed to networks not explicitly listed in the routing table. [Source: MALAMUD]
Defense Advanced Research Projects Agency (DARPA): An agency of the U.S. Department of Defense responsible for the development of new technology for use by the military. DARPA (formerly known as ARPA) was responsible for funding much of the development of the Internet we know today, including the Berkeley version of Unix and TCP/IP. [Source: NNSC]
Defense Data Network (DDN): A global communications network serving the US Department of Defense composed of MILNET, other portions of the Internet, and classified networks which are not part of the Internet. The DDN is used to connect military installations and is managed by the Defense Information Systems Agency. See also: Defense Information Systems Agency
Defense Data Network Network Information Center (DDN NIC): Often called "The NIC", the DDN NIC's primary responsibility is the assignment of Internet network addresses and Autonomous System numbers, the administration of the root domain, and providing information and support services to the DDN. It is also a primary repository for RFCs. See also: Autonomous System , network address , Internet Registry , Network Information Center , Request For Comments
Defense Information Systems Agency (DISA): Formerly called the Defense Communications Agency (DCA), this is the government agency responsible for managing the DDN portion of the Internet, including the MILNET. Currently, DISA administers the DDN, and supports the user assistance services of the DDN NIC. See also: Defense Data Network
DEK: See: Data Encryption Key
DES: See: Data Encryption Standard
dialup: A temporary, as opposed to dedicated, connection between machines established over a standard phone line.
Directory Access Protocol: X.500 protocol used for communication between a Directory User Agent and a Directory System Agent. [Source: MALAMUD]
Directory System Agent (DSA): The software that provides the X.500 Directory Service for a portion of the directory information base. Generally, each DSA is responsible for the directory information for a single organization or organizational unit. [Source: RFC1208]
Directory User Agent (DUA): The software that accesses the X.500 Directory Service on behalf of the directory user. The directory user may be a person or another software element. [Source: RFC1208]
DISA: See: Defense Information Systems Agency
Distributed Computing Environment (DCE): An architecture of standard programming interfaces, conventions, and server functionalities (e.g., naming, distributed file system, remote procedure call) for distributing applications transparently across networks of heterogeneous computers. Promoted and controlled by the Open Software Foundation (OSF), a consortium led by Digital, IBM and Hewlett Packard. [Source: RFC1208]
distributed database: A collection of several different data repositories that looks like a single database to the user. A prime example in the Internet is the Domain Name System.