The word network protocol designates a set of rules or conventions to carry out a particular task. In data transmission, the network protocol is used in a less broad sense to indicate the set of rules or specifications that are used to implement one or more levels of the OSI model. [Read more…] about What are Network Protocols? – Definition
UnGuided or also called wireless or wireless communication, transport electromagnetic waves without using a physical conductor. Instead, signals are radiated through the air (or, in a few cases, water) and therefore, are available to anyone with a device capable of accepting them. [Read more…] about UnBounded/UnGuided Transmission Media in Computer Networks
Guided means are those that provide a conductor from one device to the other and include twisted-pair cables, coaxial cables, and fiber optic cables. A signal traveling by any of these means is directed and contained by the physical limits of the medium. Twisted pair and coaxial cable use metallic (copper) conductors that accept and carry electrical current signals. Fiber optic is a glass or plastic cable that accepts and transports signals in the form of light. [Read more…] about Guided Transmission Media in Computer Networks
FDDI stands for Fiber Distributed Data Interface. It is a high-speed, high-bandwidth network based on optical transmissions. It is most often used as a network backbone, for connecting high-end computers (mainframes, minicomputers, and peripherals), and for LANs connecting high-performance engineering, graphics, and other workstations that demand a rapid transfer of large amounts of data. It can transport data at a rate of 100 Megabits per second and can support up to 500 stations on a single network. FDDI was designed to run through fiber cables, transmitting light pulses to convey information between stations, but it can also run on copper using electrical signals. It is relatively expensive to implement, although the mixing of fiber-optic with copper cabling can hold down the cost. [Read more…] about What is a Fiber Distributed Data Interface (FDDI)? – Definition
Digital Equipment Corporation (DEC) has given support to network connectivity for networks of its own and networks of other vendors also. DEC has its own architecture known as Digital Network Architecture (DNA) the product that implements the architecture is known as DEC net. The DNA was developed during 1974, to provide communication facility between various DEC systems. [Read more…] about What is the Cisco Digital Network Architecture?
The Systems Network Architecture (SNA) from IBM uses a 7 layer architecture similar to the OSI model. [Read more…] about What is SNA (System Network Architecture)?
Definition: Storage area network is abbreviated as SAN. SAN is a network which is designed to attach computer storage devices such as disk array controllers and tape libraries to servers. SAN network can be accessed by multiple computers. It is a secure and high-speed data network. It is also known as SAN storage, SAN network, etc. [Read more…] about What is a Storage Area Network (SAN)? – Definition
Long-term Evolution abbreviated as LTE. We make use of LTE to refer to wireless broadband and other mobile network technologies. LTE standard was developed by the 3GPP (3rd Generation Partnership Project) in 2004. [Read more…] about What is LTE (Long Term Evolution)?
Definition: General Packet Radio Service is a packet-based wireless communication service. It promises data rate up to 114 kbps. It is a standard technology which extends the Global system. It abbreviated as GPRS. It is designed to replace the current circuit-switched services. [Read more…] about What is General Packet Radio Service (GPRS)?
Cluster computing or High-Performance computing frameworks is a form of computing in which bunch of computers (often called nodes) that are connected through a LAN (local area network) so that, they behave like a single machine. A computer cluster help to solve complex operations more efficiently with much faster processing speed, better data integrity than a single computer and they only used for mission-critical applications. [Read more…] about What is Cluster Computing? – Definition
A Wi-Fi network is made with many amenities, such as access points, antennas, bridges, controllers, etc. In this section, we will make an overview of the equipment in order to provide some features. [Read more…] about Type of Wi-Fi equipment
A sensor array is defined as a set of sensors connected to one another, each sensor being provided with a transceiver. Sensor networks are a new generation networks with specific properties, which do not fall within the conventional architectures. [Read more…] about What is wireless sensor network (WSN)?
Mesh networks (meshed networks) are ad-hoc networks in which routing points are immobile. Customers are connected by a wireless network access points and the access points are connected by wireless links. [Read more…] about What is Wireless mesh network?
Routing is the primary element of an ad-hoc network. It takes routing software in each network node to manage the transfer of IP packets. The simplest solution is obviously to have a direct routing, as illustrated in Figure, in which each network station can directly reach another station, without going through an intermediary. The simplest case corresponds to a small cell, with a diameter less than 100 m, as in an 802.11 network in ad-hoc mode. [Read more…] about Ad-Hoc Networks Routing Protocols
Another big wireless network category is ad-hoc networks, where the infrastructure is composed as resorts themselves. The latter agreed to play the role of the router to allow the passages of information from one device to another, without these terminals are connected directly. [Read more…] about What is ad-hoc Network?
Wireless networks are developing due to the flexibility of their interface, which allows a user to change positions while staying connected. Communications between terminals can be made directly or via base stations, called access points, or AP (Access Point). Communication between access points can be wireless or cable. The flow rates of these networks are tens of megabits per second. [Read more…] about Types of Wireless Networks
The local loop is to connect users to the first node, router or switch, the operator with whom the customer has a subscription. Broadband solutions is shared between the ATM for fixed links and Ethernet for wireless backhaul. One of the objectives in the Ethernet local loop is replaced by the ATM Ethernet solutions, particularly in the xDSL modems. [Read more…] about Ethernet in the Local Loop
Ethernet on the WAN aims to transport Ethernet frames over long distances like states, countries, or the whole world, while providing quality service. Its advantages are a very low cost, the possibility of oversizing of the network, highly granular, well known technology and very simple and finally simplified management, since Ethernet is everywhere. You can go very fast in throughput with different levels of 1 and 10 Gbit/s and soon the 100 Gbit/s. The register of difficulties include the lack of reliability, packet loss less controlled and quality of services more difficult to obtain. However, several technologies are currently being developed to address these issues and provide a royal way for the arrival of Ethernet on the WAN. [Read more…] about WAN Ethernet Network
After invading the world of business, Ethernet addresses the longer distances starting with the metropolitan area. The Metro Ethernet was born of this extension. This solution is supported in different settings but especially by the Forum MEF (Metro Ethernet Forum). [Read more…] about What is Metro Ethernet Networks?
SONET (Synchronous Optical Network) is a physical level standard, proposal by Bellcore (Bell Communications Research) in the mid-80s for transmission through an optical fiber. SONET is a technique of transport between two nodes, which defines the interface adopted for the NNI (Network Node Interface). Standardized by the ANSI and recommended worldwide by the CCITT, SONET can be thought of as a physical network for a global communication system in the same way that a twisted pair LAN can see as the communication system of a corporate network. It is a potentially global network, built on fiber optic cable, with standardized data transmission speeds and recognized worldwide. SONET eliminates limits between telephone companies worldwide.
[Read more…] about What is Synchronous Optical Networking (SONET)? – Definition
The LAP-F protocol (Link Access Protocol-Frame) was born with frame relay, designed to improve the performance of networks from the X.25 recommendation UITT. The latter has proved too heavy and therefore unable to increase rates, it took in search for a simplification. [Read more…] about LAP-F protocol
The frame level (layer 2) is to render a service to the next level just. This service is a transport node to node packet. Specifically, its role is to transport a package of three or message fragment layer of layer 4 from one node to another node. For this, the frame level asks his turn at just below, the physical level, a service of conveying the bits of the frame from one node to another node. This section provides the features necessary to achieve all these actions. [Read more…] about Frame-level Architecture
Applications that are conventionally used on terminal equipment put in implement a point-to-point communication, that is to say the part of the communication micro to go look for information to only one other point. Many other applications involve the cooperation of several processes. For example, a search in a distributed database in which information is spread across multiple sites, uses a simultaneous request for information to several centers. To make this request, the application and all associated protocol layers must manage multipoint. This way of communicating is more powerful than that which is to apply a first site, and once the response, a second, and so on. [Read more…] about Multi-point Architectures
The application of methods derived from INFORMATION THEORY to the detection and correcting of errors in DIGITAL data streams. Error correction is of the utmost importance in most areas of computing and communications technology. For example: Internet’s TCP protocol provides error detection, CD-ROMS devote around 14% of their total data capacity to redundant error correction information (and music CDS only a little less), and modem speeds above 28 kilobits per second would be impossible over public telephone lines without error correcting PROTOCOLS such as v.90. [Read more…] about What is Error Detection and Correction?
(xDSL) A whole class of digital telecommunication technologies that can offer BROADBAND data rates, up to 50 megabits per second (Mbps), over the existing copper wires of the analogue public telephone system. By employing advanced modulation schemes, xDSL technologies support Internet or other data access simultaneously with voice telephone calls. In the meta-acronym xDSL, the x stands for the first letter of any of the individual acronyms used for these technologies: ADSL, HDSL, SDSL and VDSL. [Read more…] about What is DSL (Digital Subscriber Line)?
In the world of asynchronous communication (over Mac or PC serial ports), CTS stands for clear to send. When a computer needs to communicate with an outside device physically connected to it (peripheral), the two of them have to go through this preamble of making sure each of them is ready to hear what the other has to say, and confirm that they are going to be speaking the same language. Somewhere near the beginning of this preamble, one device will send an RTS (Request To Send) message. The receiving device will then reply with a CTS message “Yes, I’m now ready for anything you want to send me.” I know, the whole thing sounds like you may be sitting there drumming your fingers on your desk, waiting for these flipping machines to get done with their senseless checklist. Relax. Like most processes done by a computer, this one takes less than a millisecond.
BBS (Bulletin Board System): A single computer running special communications software that acts as a kind of electronic bulletin board. That allows remote users to dial in via a public telephone line to exchange messages and chat with one another. which is a service usually set up by an organization or a club to provide or exchange information. A BBS allows multiple people to use it at the same time in order to exchange ideas, offer help with software problems, and converse (through typed conversations) with other users currently connected to the BBS. You access the BBS through your modem , a device that transmits data through ordinary telephone lines. While connected to a BBS, a user can share information with other computer users, leave messages, and upload and download programs. One popular BBS is the Boston Computer Exchange, a place where members can buy, sell, or trade computers. Pay-for-use information services, such as CompuServe, Prodigy, and Internet are like BBS, but much larger. There are thousands of other BBSs across the globe offering a variety of topics and interests ranging from software support to dating services. To communicate with other computers, a modem is necessary. [Read more…] about What is BBS (Bulletin Board System)?
AAL (ATM Adaptation Layer) is a third example message level protocol. A software layer that accepts user data, such as digitized voice, video or computer data, and converts to and from cells for transmission over an ASYNCHRONOUS TRANSFER MODE network. AAL software mostly runs at the end-points of a connection, though in a few circumstances AAL software is run inside an ATM switch. AAL includes facilities to carry traffic that uses other network protocols, such as TCP/IP, over ATM. [Read more…] about What is ATM Adaptation Layer (AAL)?
Definition: Asynchronous Transfer Mode (ATM) also called cell relay (transferring data in cells of a fixed size) that is operates at the data link layer (Layer 2) of OSI Model over fiber or twisted-pair cable, a high-speed switched network technology based on ITU-T Broadband Integrated Services Digital Network (B-ISDN) standard, developed by the telecommunications industry to implement the next generation network. ATM was designed for use in WANs such as the public telephone system and corporate data networks, though it has also been applied to create super-fast LANs. [Read more…] about What is ATM (Asynchronous Transfer Mode)? Definition
ISDN provides two basic types of interfaces to users. [Read more…] about ISDN User Interfaces