A terminal having local processing capability. It has a built-in CPU and can perform specific functions such as editing data, controlling other terminals etc.
A blog About Computer Science and has many topics or post related to networking, hardware, software and more about in Computer science.
Saturday, November 30, 2013
ISDN
ISDN stands for Integrated Service Digital Network. A special phone line that supports modem speeds up to 64 Kbps. However, these phone line can be quite expensive to acquire. Many ISDN adapters supports two channel access.
IGRP
IGRP stands for Interior Gateway Routing Protocol. An interior routing protocol developed by Cisco to address the problems associated with routing in large, hetrogenious networks.
IEEE 802.5
Standard for token ring access methods and physical layer specifications that is common token ring architecture. It becomes the basis of ISO/IEC 8802-5. The current version was approved in 1995.
IEEE 802.4
Standard for token passing bus access methods and physical layer specifications. It was approved in 1990.
IEEE 802.3Z
Proposed standard for Physical layer, repeater and management parameters for 1000 Mbps operation, often referred to as 'Gigabit Ethernet'.
IEEE 802.3Y
Proposed physical layer specification for 100 Mbps operation on two pair of Category 3 or better balanced twisted pair cable that is 100Base-T2.
See Also :-
See Also :-
IEEE 802.3W
Proposed standard for enhanced MAC algorithms.
MAC stands for Media Access Control. Lower of the two sublayers of data link layer defined by the IEEE. The MAC sublayer handles access to shared media, such as whether token passing or contention will be used.
See Also :-
MAC stands for Media Access Control. Lower of the two sublayers of data link layer defined by the IEEE. The MAC sublayer handles access to shared media, such as whether token passing or contention will be used.
See Also :-
IEEE 802.3V
Standard for supporting 150 ohm cables in 10Base-T link segments. Approved in 1995 and incorporated into ISO/IEC 8802-3.
IEEE 802.3U
Supplement to 802.3 covering MAC parameters, the physical layer, and repeaters for 100 Mbps operation that is, 100 Base-T, generally known as Fast Ethernet. It was approved in 1995.
IEEE 802.3T
Standard for supporting 120-ohm cables in 10Base-t simplex link segments. It was approved in 1995 and incorporated into ISO/IEC 8802-3.
IEEE 802.3R
The standard for the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) access method and physical layer specifications using 10Base-5. It was updated in 1996.
IEEE 802.3Q
Guidlines for the development of managed objects. It was approved in 1993 and incorporated into ISO/IEC 8802-3.
IEEE 802.3P
Standard for the 10 Mbps base-band media attachment units layer manegement. It was approved in 1993 and incorporated into ISO/IEC 8802-3.
IEEE 802.3K
Standard for layer management for 10 Mbps baseband repeaters. Approved in 1992, it was incorporated into ISO/IEC 8802-3.
IEEE 802.3J
Standard for 10 Mbps active and passive star base segments using fiber optics-that is, 10base-F. It was approved in 1993 and incorporated into ISO/IEC 8802-3.
IEEE 802.3I
Standard covering two areas: Multisegment 10 Mbps baseband networks and twised pair media for 10Base-T networks. It was approved in 1990 and incorporated into ISO/IEC 8802-3. Also Conformance statement for the 10Base-T media attachment unit protocol. It was approved in 1992 and incorporated into ISO/IEC 8802-3.
IEEE 802.3H
Standard for layer management in Carrier Sense Multiple Access with Collision Detection (CSMA/CD) networks. It was approved in 1990 and incorporated into ISO/IEC 8802-3.
IEEE 802.3E
Standard for physical signaling, media attachment, and base-band media specifictions, for a 1 Mbit/sec network into ISO/IEC 8802-3.
IEEE 802.3D
Standard for media attachment units and base-band media specifications over fiber-optic repeater links. It was approved in 1987 and incorporated into ISO/IEC 8802-3.
IEEE 802.3C
Standard for 10Mbps baseband repeaters. Approved in 1985 and incorporated into ISO/IEC 882-3.
IEEE 802.3b
Standard for broadband media attachment unit and specifications for 10Broad36. It was approved in 1985 and incorporated into ISO/IEC 8802-3.
IEEE 802.311
Standard for wireless LAN MAC and physical layer specifications. Current drafts and focus on the 2.4 GHz band.
IEEE 802.3
Standard for LAN based Carrier Sense Multiple Access with Collision Detection (CSMA/CD) access methods and physical layers, as well as the basis of ISO/IEC 8802-3. This is sometimes referred to as the 'Ethernet standard'. It was revised in 1996.
IEEE 802.12
Standard for 100 Mbps demand priority access method Physical layer and repeater specifications, also known as 100VG-AnyLAN. It was approved in 1995.
Wednesday, November 27, 2013
Sunday, November 17, 2013
ICMP
ICMP stands for Internet Control Message Protocol. Network Layer TCP/IP protocol that reports errors and provides other information relevant to IP packet processing. Documented in RFC 792.
HTML
HTML stands for HyperText Markup Language. This is the format used for wirting documents to be viewed with a World Wide Web browser. Items in the document can be text, image, sounds, and links to other HTML documents or sites, services and resources on the Internet.
Hypertext
A metaphor for presenting information in which text, images, sounds and actions become linked together in a complex, non-sequential web of associations that permit the user to browse throught related topics, regardless of the presented order of the topics. These links are often established both by the author of a hypertext document and by the user, depending on the intent of the hypertext document.
Hub and spoke Topology
A topology that consists of one central network and a set of remote networks each with one connection to the central network and no direct connections to each other. Traffic between remote networks goes through the hub network.
Hub
A network device where the information flow is accumulated and then distributed to various groups and users. It can be used between users on the same LAN and users on different LANs. One of the most essential components in a network. Hubs are devices that serve as the central point where cables from all nodes come together. Hubs are available in all shapes and sizes. There are dumb hubs which simply pass on the signals from one node to another. Smart hub are also there that provide limited management capabilities. There are also intelligent hubs, which support multiple LANs and topologies, provide extensive management capabilities, and can ever house other module types, such as routers and qbridges. Active and passive hubs are also there. Active hubs functions as repeaters, and passive hubs simply tiport repeater, sometimes referred to as a concentrator.
HTTP
HypetText Transport Protocol, the Internet protocol that defines how a Web server responds to requests for files, made via anchors and URLs.
HSRP
HSRP stands for Host Standby Router Protocol. Provides high network availability and transparent network topology changes. HRSP creates a Host Standby router group with a lead router that services all packets sent to the Host standby address. The lead router is monitored by other routers in the group, and if it fails, one of these standby routers inherits the lead position and the Host Standby group address.
Host-based Security
The technique of securing an indiviudaul system from attack. Host based security is an operating system and version dependent.
Hop Count
Routing matric used to measure the distance between a source and a destination in a number of routers or hops between the source and destination. Also in routing, the number of links the must be crossed to get from any given source node to any given destination node. The destination network cannot be more than 16 hops (servers or routers) from the source.
Hop
Term describing the passage of data packet between two network nodes (for examples, between two routers).
Hold Down
State into which a route is placed so routers will neither advertise the route nor accept advertisements about the route for a specific length of time (the hold-down peroid). Hold-down is used to flush bad information about a route from all routers in the network.
Hierarchical Routing
A model for distributing knowledge of a network topology among internetwork routers. With hierarchical routing, no single router needs to understand the complete topology.
Hierarchical Network Design
A technique for designing scalable campus and enterprise network topologies using a layered, modular model.
Hierarchical Network
A communications network in which computers or processors are connected in a tree-like structure. In Usernet, the organisation of newsgroups into general areas, topics and subtopics, or the major groupings themselves.
What is Computer Hardware
The physical components of a computer system such as electronic, magnetic and mechanical devices.
Hardware is a machinery or equipment, such as a CPU, video terminal, disk drive and printer. Any electronic, mechanical or electro-mechanical device is hardware.
Hardware is a machinery or equipment, such as a CPU, video terminal, disk drive and printer. Any electronic, mechanical or electro-mechanical device is hardware.
What is Handshaking
Handshaking are the signals transmitted back and forth over a communications network that establish a valid connection between two parties. Handshaking is part of the communications protocol that dictates the codes and electronic signalling required.
Process whereby two protocol entities synchronize during connection established.
Process whereby two protocol entities synchronize during connection established.
Handshake
A trade term that refers to what takes place when two computers or a computer and a terminal device are interconnected in such a way that they can exchange information.
Half Duplex
Capability for data transmission in only one direction at a time between a sending station and a receiving station.
Hacker
A computer adept, some one who enjoys working with computers and testing the limits of systems, and enthusiastic or fast (or both) programmer. Outside of the Internet, the word hacker has unsavory connotations, suggesting someone who breaks into computer network and steals or vandalizes information. On the Internet, such malevolent hackers are called crackers.
H.320
Suite for international standard Specifications for videoconferecing over circuit-switching media such as ISDN, fractional T1, or switched-56 lines.
Group Band
A group consists of fields that appear together based on some criteria that you specify by choosing the Data Grouping... option on the Report menu.
Gopher
Gopher is an information gathering tool used for Internet that offers a smooth, menu-driven way to traverse international "gopherspace" -- which these days literally means several hundred servers worldwide, offering text, computer programs, audio, still images, and even movie clips. It provides a seamless, "hidden programming" interface with which you can transfer files, browse databases, and telnet to sites around the globe, simply and easily.
Goodput
Generally referring to the measurement of actual data successfully transmitted from the sender (s) to receiver (s). In an ATM network, this is often a more useful measurement than the number of ATM cell-per-second throughput of an ATM switch if that switch is experiencing cell loss that results in many incomplete, and therefore unusable, frames arriving at the recipient.
Friday, November 15, 2013
Gigabit Ethernet
1000-Mbps LAN technologies specified in IEEE 802.3z. Gigabit Ethernet offers a speed increase 100 times that of the original IEEE 802.3 specification, while preserving such qualities as frame format, MAC mechanisms, and frame size.
GGSN
GGSN stands for Gateway GPRS Support Node. This is a router that serveras a gateway between mobile networks and packet data networks.
Gateway
A device that is used to interface two otherwise incompatible network facilities. Also a term used in networking. It is a computer providing a connection between two networks, two E-mail handling systems, or a Usenet newsgroup and a mailing list. A gateway reformats the data so that it will be acceptable to the system it is passing into. A shared connection between a local area network and a larger system, such as a Mainframe computer or a large packet switching network, whose communications protocols are different. Usually slower than a bridge or a router, a gateway is a combination of hardware and software with its own processor and memory used to perform protocol conversions.
Full Mesh
Term describing a network in which devices are organised in a mesh topology, with each network node having either a physical circuit or a virtual circuit connecting it to every other network node.
Full Duplex
A method of using communocation channel in which signals can be transmitted between a source and a destination in both directions simultaneously. Also capability for simultaneous data transmission beween a sending station and a receivimg station.
Frequency Division Multiplexing (FDM)
A method used for concurrently transmit data between several transmitters and receivers over a single transmission medium. The availabel bandwidth of a physical medium is divided into smaller, disjointed logical bandwidths and each of the componet bandwidths is used is a separate communications line (channel).
Frame Relay Nework
A telecommunications network based on frame relay technology. In this technology, data is multiplexed.
Frame Relay
Industry standard, switched data-link layer protocol that handles multiple virtual circuits between connected devcies. Frame Relay is more efficient than X.25, the protocol for which it is generally considered a replacement.
Frame
The basic package of information on a network channel. Also logical grouping of information sent as a data link layer unit over a transmission medium. Often refers to the header and trailer, used for synchronization and error control, that surround the user data contained in the unit.
Fragmentation
Process of breaking a packet into smaller units when transmitting over a network medium that cannot support the original size of the packet.
Flooding
Traffic-passing technique used by switches and bridges, in which traffic received on an interface is sent out all interfaces except the interface on which the information was received.
Flat Network Design
A network design that has little or no hierarchy or modularity and is generally only approproate for small shared or switched LANs.
File Server Architecture
A configuration of computers on a network that is similar to a client/server architecture, except that the server is mostly a repository of a data on which it cannot itself perform queries or processing. When a client needs to make a query, the server sends all data that could possible be relevant over the network, which is not efficient. Hence this approach is replaced by client/server architecture.
Fiber-Optic Cable
Physical medium capable of conducting modulated light transmission. Fiber-optic cable is not susceptible to electromagnetic interference, and is capable of high data rates. Also a data transmission medium made of tiny threads of glass or plastic that can transmit huge amount of information at the speed of light.
Fast Ethernet
An improved version of the Ethernet, Fast Ethernet provides customers with a flexible and affordable way to scale network performance and interoperate with a wide range of other networking technologies. It is unique tool for an enterprise to augment the throughput and performance of existing LANs, with a cost-effective high-speed connectivity option for linking work groups and servers. Also any of a number of 100-Mbps Ethernet specifications. Fast Ethernet offers a speed increase ten times that of the original IEEE 802.3 Specification, while preserving such qualities as frame format, MAC mechanisms and frame size.
Facsimile (FAX)
Transmission of pictures, texts, maps, graphs, etc over transmission lines, phone lines, and other carriers between geographically separated points. An image is scanned at a transmitting point and duplicated at a receiving point.
Faceplate
A connecting point in a cable system that permits a network cable from a movable computer to connect with a permanently installed cable system. This is generally a plate installed in the wall.
Extranet
An extranet is the part of a corporate intranet that allows companies to communicate with the intranets of their customers and suppliers, facilitating electronic transactions.
Extended ASCII
Extended ASCII provides added capability by allowing for 128 additional characters, such as accented letters, graphic characters and special symbols.
Executive Workstation Expert System
Special desktop computer-based units designed for busy people who do not linke of type. They have special function keys, and may accept input through the use of a mouse or a touch screen. They have the ability to perform word/data processing, manage data bases, produce graphics and support many other activities.
Executive Routine
A master program in an Operation System (OS) that controls the execution of other programs. It is also known as the executive, monitor or supervisor.
Ethernet Switch
A network service that manages traffic between workstation, usually when there are many sources of information in a network.
EPON
Ethernet Passive Optical Network. This is a passive access loop of Ethernet that supports channelisation to guarantee bandwidth to each access mode.
Enterprise Network
Large and deliverse internetwork connecting most major points in an origination. An enterprise network typically consists of building and campus networks, remote-access services, and one or more WANs.
Enhanced Interior Gateway Routing Protocol
Advanced Version of IGRP developed by Cisco. Provides superior convergence properties and operating efficiency, and combines the advantages of link-state protocols with those of distance-vector protocols.
Encryption
Converting stored or transmitted data to a coded form in order to prevent it from being read by unauthorized persons. Also application of a specific algorithm to alter the appearance of data, making it incomprehensible to those who are not authorized to see the information.
Encapsulating Bridging
A bridging method for connecting LANs across a network of a different type, for example, connecting Ethernet LANs via an FDDI backbone. The entire frame from one network is placed inside the frame used by the data-link layer protocol of the other network.
EMMS
Electronic Mail/Message System is a system that can store and deliver, by electronics means, text and messages that would otherwise be forwarded through the postal service or sent verbally over telephone lines.
A general term to describe the transmission of message by the use of computing systems and telecommunications facilities.
Electronics Funds Transfer (EFT)
Electronics Funds Transfer (EFT) is a general term referring to a cashless approach used to pay for goods and services.
EDI (Electronic Data Interchange)
EDI (Electronic Data Interchange) is the transfer of electronic messages from one company to another using a network. Companies use EDI to facilitate business-to-business transactions like purchase orders, purchase confirmations, invoices, and payments. EDI messages can be exchanged using a WAN or the Internet.
ELAN
Emulated LAN, ATM network in which an Ethernet or Token Ring LAN is emulated using a client/server model. ELANs are composed of an LEC, an LES, a BUS, and a LECS. ELANs are defined by the LANE specification.
EISA Bus
Acronym for Extended Industry Standard Architecture, a bus standard introduced in 1988 by a consortium of nine computer-industry companies. This 32 bit bus was developed which was backward compatible with the existing expansion boards. It can accept ISA bus cards.
E-LAN/E-Line
The Ethernet Line (E-Line) service is a strictly point-to-point service, whereas E-LAN (Ethernet LAN) is either a point-to-multipoint or multipoint-to-multipoint service. In case of video delivery on an E-LAN, a master will take control to deliver service on request over point-to-multipoint services.
Thursday, November 14, 2013
Dynamic SLIP
A type of SLIP access to the Internet, in which the user is supplied with a new IP address, drawn from a pool of possibilities every time he/she connects. This enables the service provider to assign fewer IP addresses to its SLIP customers, with the trade-off being that the users can not function as a host without a consistent address.
DVMRP
Distance-Vector Multicast Routing Protocol. Multicast routing protocol, largely based on RIP. Packets are forwarded on all outgoing interfaces until pruning occurs. Defined in RFC 1075.
Duplex
A data communication facility on which data can be transmittd in two directions. A facility where information travels both ways.
Dual Homed Gateway
A dual-homed gateway is a system that has two or more network interfaces, each of which is connected to a different network. In firewall configurations, a dual-homed gateway usually acts to block or filter some or all of the traffic trying to pass between the networks.
DTE (Data Terminal Equipment)
Data Terminal Equipment. Device at the user end of a user-network interface that serves as a data source, destination, or both. DTE connects to a data network through a DCE device (for example, a modem) and typically uses clocking signals generated by the DCE. DTE includes such devices as computers, internetworking devices, and multiplexers.
DNS spoofing
Assuming the DNS name of another system by either corrupting the name service cache of a victim system, or by compromising a domain name server for a valid domain.
Distribution Layer
Connects network services to the access layer in a hierarchical topology, and implements policies regarding security, traffic loading and routing.
Distributing Data Processing
The decentralization of a computer system through the use of multiple computers interconnected by a communications network. It facilitates data processing capabilities at the location of the end user.
Wednesday, November 13, 2013
Distance Vector Routing Algorithm
Class of routing algorithms that call for each router to send its routing table in periodic update packets to its neighbors.
Discontiguous Subnet
An IP subnet that is made up of two or more physical networks that are separated by routers.
Directory Access Protocol (DAP)
An X-500 protocol governing communication between a directory user agent and a directory system agent.
Direct Sequence Spread Spectrum
A form of spread spectrum in which each bit in the original signal is represented by multiple bits in the transmitted signal, using a spreading code.
Digital Transmission
The transmission of digital data, using either an analog or digital signal, in which the digital data are recovered and repeated at intermediate points to reduce the effects of noise.
DDR (Dial-on-Demand Routing)
Dial-on-Demand Routing is a Technique whereby a router can automatically initiate and close a circuit-switched session as transmitting stations demand.
DCE (Data Communication Equipment)
Data Communication Equipment or Data Circuit-terminating Equipment devices and connections of a communications network that comprise the network end of the user-to-network interface. Modems and interface cards are examples of DCE.
Datagram
In packet switching, a packet, independent of other packets, that carries information sufficient for routing from the originating data terminal equipment (DTE) to the destination DTE without the necessity of establishing a connection between the DTEs and the network.
Data Communication System
A system consisting of carriers and related devices used to transport data from one point to another.
Data Link Layer
Layer 2 of the OSI reference model. This layer provides reliable transmit of data across a physical link. The data-link layer concerned with physical addressing, network topology, line discipline, error notification, ordered delivery of frames, and flow control. The IEEE has divided this layer into two sublayers: the MAC sublayer and the LLC sublayer.
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