Frame relay, also found written as frame-relay, is an efficient data transmission technique used to send digital information quickly and cheaply in a relay of frames to one or many destinations from one or many end-points. Network providers commonly implement frame relay for voice and data as an encapsulation technique, used between local area networks (LANs) over a wide area network (WAN). Each end-user gets a private line (or leased line) to a frame-relay node. The frame-relay network handles the transmission over a frequently-changing path transparent to all end-users.

As of 2006, ATM and native IP-based protocols have begun, slowly, to displace frame relay. With the advent of the VPN and other dedicated broadband services such as cable modem and DSL, the end may loom for the frame relay protocol and encapsulation. There are, however, many rural areas where DSL and cable modem service are not available and the least expensive type of "always-on" connection is a 128-kilobit frame relay line. Thus a retail chain, for instance, may use frame relay for connecting rural stores into their corporate WAN (probably with a VPN encryption layer for security).

Frame Relay description

The designers of frame relay aimed at a telecommunication service for cost-efficient data transmission for intermittent traffic between local area networks (LANs) and between end-points in a wide area network (WAN). Frame relay puts data in variable-size units called "frames" and leaves any necessary error-correction (such as re-transmission of data) up to the end-points. This speeds up overall data transmission. For most services, the network provides a permanent virtual circuit (PVC), which means that the customer sees a continuous, dedicated connection without having to pay for a full-time leased line, while the service-provider figures out the route each frame travels to its destination and can charge based on usage.

An enterprise can select a level of service quality - prioritizing some frames and making others less important. A number of service providers, including AT&T, offer frame relay. Frame relay can run on fractional T-1 or full T-carrier system carriers. Frame relay complements and provides a mid-range service between ISDN, which offers bandwidth at 128 kbit/s, and Asynchronous Transfer Mode (ATM), which operates in somewhat similar fashion to frame relay but at speeds from 155.520 Mbit/s or 622.080 Mbit/s.

Frame relay has its technical base in the older X.25 packet-switching, designed for transmitting analog data such as voice conversations. Unlike X.25, whose designers expected analog signals, frame relay offers a fast packet technology, which means that the protocol does not attempt to correct errors. When a frame relay network detects an error in a frame, it simply "drops" that frame. The end points have the responsibility for detecting and retransmitting dropped frames. (However, digital networks offer an incidence of error extraordinarily small relative to that of analog networks.)

Frame relay often serves to connect local area networks (LANs) with major backbones as well as on public wide-area networks (WANs) and also in private network environments with leased lines over T-1 lines. It requires a dedicated connection during the transmission period. Frame relay does not provide an ideal path for voice or video transmission, both of which require a steady flow of transmissions. However, under certain circumstances, voice and video transmission does use frame relay.

Frame relay relays packets at the data link layer (layer 2) of the Open Systems Interconnection (OSI) model rather than at the network layer (layer 3). A frame can incorporate packets from different protocols such as Ethernet and X.25. It varies in size up to a thousand bytes or more.

Frame Relay was originally developed as an extension of Integrated Services Digital Network (ISDN). It was designed to enable the circuit-switched technology to be transported on a packet-switched network. The technology has become a stand-alone and cost-effective means of creating a WAN.

Frame Relay switches create virtual circuits to connect remote LANs to a WAN. The Frame Relay network exists between a LAN border device, usually a router, and the carrier switch. The technology used by the carrier to transport the data between the switches is not important to Frame Relay.

The sophistication of the technology requires a thorough understanding of the terms used to describe how Frame Relay works. Without a firm understanding of Frame Relay, it is difficult to troubleshoot its performance.

Frame Relay has become one of the most extensively used WAN protocols. One reason for its popularity is that it is inexpensive compared to leased lines. Another reason Frame Relay is popular is that configuration of user equipment in a Frame Relay network is very simple.

Frame Relay frame structure is essentially identical to that defined for Lap-D.The frame relay format can be distinguished from Lap-D by its absence of a control field.

Each frame relay PDU consists of the following fields:

1. Flag Field. The flag is used to preform high level data link synchronization which indicates the beginning and end of the frame with the unique pattern 01111110. To ensure that the 01111110 pattern does not appear somewhere inside the frame, bit stuffing and destuffing procedures are used.
2. Address Field. Each address field may occupy either octet 2 to 3, octet 2 to 4, or octet 2 to 5, depending on the range of the address in use. A two-octet address field comprising the EA=ADDRESS FIELD EXTENSION BITS and the C/R=COMMAND/RESPONSE BIT.
3. DLCI-Data Link Connection Identifier Bits. The DLCI is used to identify the virtual connection so that the receiving end knows which information connection this frame belongs to. It should be pointed out that this DLCI has only local significance. Several virtual connections can be multiplexed over the same physical channel.
4. FECN, BECN, DE BITS. These are congestion reporting capability bits:
• FECN=Forward Explicit Congestion notification bit
• BECN=Backward Explicit Congestion Notification bit
• DE=Discard Eligibility bit
5. Information Field. The maximum number of data bytes that may be put in a frame is a system parameter. The actual maximum frame length may be negotiated at call set-up time. The standard specifies that the maximum information field size (to be supported by any network) is at least 262 octets. Since end-to-end protocols typically operate on the basis of larger information units, it is recommended that the network support the maximum value of at least 1600 octets, to avoid the need for segmentation and reassembling by end users.
6. Frame Check Sequence (FCS) Field. Since the bit error rate of the medium is not completely negligible, it is necessary to implement error detection at each switching node to avoid wasting bandwidth due to the transmission of erred frames. The error detection mechanism used in frame relay is based on the Cyclic Redundancy Check (CRC).

The frame relay network uses a simplified protocol at each switching node. The simplicity is achieved when link-by-link flow control is missing. As a result, the performance of frame relay networks has largely been determined by the offered load. When the offered load is high, due to the bursts in some services, temporary overload at some frame relay nodes causes a collapse in network throughput. Therefore, some effective mechanisms are required to control the congestion.

The congestion control in Frame Relay networks includes the following elements:

1. Admission Control. This is the principle mechanism used in frame relay to ensure that resource requirement, once accepted, can be guaranteed. It is also generally used to achieve high network performance. The network decides whether to accept a new connection request based on the relation of the requested traffic descriptor and the network's residual capacity. The traffic descriptor is defined as a set of parameters communicated to the switching nodes at call set-up time or service subscription time, which characterizes the connection's statistical properties. The traffic descriptor consists of three elements:
2. Committed Information Rate (CIR). The average rate (in bit/s) at which the network guarantees to transfer information units over a measurement interval T. This T interval is defined as: T = Bc/CIR .
3. Committed Burst Size (BC). The maximum number of information units that can be transmitted during the interval T.
4. Excess Burst Size (BE). The maximum number of uncommitted information units (in bits) that the network will attempt to carry during the interval

Once a connection has been established in the network, the edge node of the frame relay network must monitor the connection's traffic flow to ensure that the actual usage of network resources does not exceed this specification. Frame relay defines some restrictions on the user's information rate. It allows the network to enforce the end user's information rate and discard information when the subscribed access rate is exceeded.

Explicit congestion notification is proposed as the congestion avoidance policy. It tries to keep the network operating at its desired equilibrium point so that a certain QOS for the network can be met. To do so, special congestion control bits have been incorporated into the address field of the frame relay: FECN and BECN. The basic idea is to avoid data accumulation inside the network. FRAME RELAY VS. X.25

X.25 was designed to provide error-free delivery using high error-rate links. Frame relay takes advantage of the new, lower error rate links, enabling it to eliminate many of the services provided by X.25. The elimination of functions and fields, combined with digital links, enables frame relay to operate at speeds 20 times greater than X.25.

X.25 is defined for layers 1, 2 and 3 of the ISO model, while frame relay is defined for layers 1and 2 only. This means that frame relay has significantly less processing to do at each node, which improves throughput by order of magnitude.

X.25 prepares and sends packets, while frame relay prepares and sends frames. X.25 packets contain several fields used for error and flow control, none of which is needed by frame relay. The frames in frame relay contain an expanded address field that enables frame relay nodes to direct frames to their destinations with minimal processing .

X.25 has a fixed bandwidth available. It uses or wastes portions of its bandwidth as the load dictates. Frame relay can dynamically allocate bandwidth during call setup negotiation at both the physical and logical channel level.

X.25 origins

Frame relay began as a stripped-down version of the X.25 protocol, releasing itself of the error-correcting burden most commonly associated with X.25. When an error is detected, the packet is simply dropped. Frame relay uses the concept of shared-access and relies on a technique refered to as best-effort, whereby error-correction is practically non-existent and reliable data delivery is practically unguaranteed. It is an industry-standard encapsulation utilizing the strengths of high-speed, packet-switched technology able to service multiple virtual circuits and protocols between connected devices, such as two routers.

Virtual circuits

As a WAN protocol, frame relay is most commonly implemented at Layer 2 (data link layer) of the Open Systems Interconnection (OSI) seven layer model. Two types of circuits exist: permanent virtual circuits (PVCs) which are used to form logical end-to-end links mapped over a physical network, and switched virtual circuits (SVCs). The latter analogous to the circuit-switching concepts of the public-switched telephone network (or PSTN), the global phone network we are most familiar with today. While SVCs exist and are part of the frame relay specification, they are rarely applied to real-world scenarios. SVCs are most often considered harder to configure and maintain and are generally avoided without appropriate justification.

Local Management Interface (LMI)

Initial proposals for Frame Relay were presented to the Consultative Committee on International Telephone and Telegraph (CCITT) in 1984. Lack of interoperability and standardisation, prevented any significant Frame Relay deployment until 1990 when Cisco, Digital Equipment Corporation (DEC), Northern Telecom, and StrataCom formed a consortium to focus on its development. They produced a protocol that provided additional capabilities for complex inter-networking environments. These Frame Relay extensions are referred to as the Local Management Interface (LMI).

Datalink Connection Identifiers (or DLCIs) are numbers that refer to paths through the frame relay network. They are only locally significant, which means that when device-A sends data to device-B it will most-likely use a different DLCI than device-B would use to reply. Multiple virtual circuits can be active on the same physical end-points (performed by using subinterfaces).

Committed Information Rate (CIR)

Frame relay connections are often given a Committed Information Rate (CIR) and an allowance of burstable bandwidth known as the Extended Information Rate (EIR). The provider guarantees that the connection will always support the CIR rate, and sometimes the EIR rate should there be adequate bandwidth. Frames that are sent in excess of the CIR are marked as "discard eligible" (DE) which means they can be dropped should congestion occur within the frame relay network. Frames sent in excess of the EIR are dropped immediately.

Market reputation

Frame relay was designed to make more efficient use of existing physical resources, which allow for the overprovisioning of data services by telecommunications companies (telcos) to their customers, as most clients were unlikely to be utilizing a data service 100 percent of the time. In more recent years, frame relay has acquired a bad reputation in some markets because of excessive bandwidth overbooking by these telcos.

Frame relay is/was often sold by telcos to businesses looking for a cheaper alternative to dedicated lines; its use in different geographic areas depended greatly on governmental and telecommunication companies policies. Some of the early companies to make frame relay products were StrataCom (later acquired by Cisco Systems) and Cascade Communications (later acquired by Ascend Communications and then Lucent Technologies

Sound

A schematic representation of hearing. (Blue: sound waves. Red: eardrum. Yellow: cochlea. Green: auditory receptor cells. Purple: frequency spectrum of hearing response. Orange: nerve impulse.)

Sound is vibration, as perceived by the sense of hearing. We usually hear vibrations that travel through air, but sound can also travel through gases, liquids and solids. It cannot travel through a vacuum (such as exists in outer space). When the vibrations reach our ears, they are converted into nerve impulses that are sent to our brains, allowing us to perceive the sound.

In more technical language, sound "is an alternation in pressure, particle displacement, or particle velocity propagated in an elastic material" (Olson 1957) or series of mechanical compressions and rarefactions or longitudinal waves that successively propagate through media that are at least a little compressible (solid, liquid or gas but not vacuum). In sound waves parts of matter (molecules or groups of molecules) move in a direction of the spreading of the disturbance (as opposite to transversal waves). The cause of sound waves is called the source of waves, e.g., a violin string vibrating upon being bowed or plucked.

A sound wave is usually represented graphically by a wavy, horizontal line; the upper part of the wave (the crest) indicates a compression and the lower part (the trough) indicates a rarefaction.

Attributes of sound

The characteristics of sound are frequency, wavelength, amplitude and velocity.

Frequency and wavelength

The frequency is the number of air pressure oscillations per second at a fixed point occupied by a sound wave. One single oscillatory cycle per second corresponds to 1 Hz. The wavelength is the distance between two successive crests and is the distance that a wave travels in the time of one oscillatory cycle.

The wavelength of a sound wave of frequency f and travelling at speed c is given by c/f. Given a speed of 343 m/s, a 20 kHz sound wave has a wavelength of about 17 mm. For comparison, an A440 has a nominal wavelength of about 78 cm, and a 20 Hz sound wave has a wavelength of 17 m.

Amplitude

The amplitude is the magnitude of sound pressure change within the wave, or basically, the maximum amount of pressure at any point in the sound wave. A sound wave is caused literally by increases in pressure at certain points (of a material) causing a "domino effect" outward, the high pressure points are the crests mentioned above, and behind them are low pressure points which tail them, those are the troughs mentioned above. Amplitude is the maximal displacement of particles of matter that is obtained in compressions, where the particles of matter move towards each other and pressure increases the most and in rarefactions, where the pressure lessens the most. See also particle displacement and particle velocity. While the pressure can be measured in pascals, the amplitude is more often referred to as sound pressure level and measured in decibels, or dBSPL, sometimes written as dBspl or dB(SPL). When the measurement is adjusted based on how the human ear perceives loudness based on frequency, it is called dBA or A-weighting. See decibels for a more thorough discussion.

• Chart showing decibel level of many sounds

Velocity

Sound's propagation speed depends on the type, temperature and pressure of the medium through which it propagates. Under normal conditions, however, because air is nearly a perfect gas, the speed of sound does not depend on air pressure. In dry air at 20 °C (68 °F) the speed of sound is approximately 343 m/s (approximately 1 meter every 2.9 milliseconds). The speed of sound relates frequency to wavelength. Thus, a tone of 343 Hz (F4 minus 31 cents) traveling in air has a wavelength of 1 meter.

Types of sounds

Noises are irregular and disordered vibrations including all possible frequencies. Their wave diagram does not repeat in time. Noise is an aperiodic series of waves.

Sounds that are sine waves with fixed frequency and amplitude are perceived as pure tones. While sound waves are usually visualised as sine waves, sound waves can have arbitrary shapes and frequency content, limited only by the apparatus that generates them and the medium through which they travel. In fact, most sound waves consist of multiple overtones or harmonics and any sound can be thought of as being composed of sine waves (see additive synthesis). Waveforms commonly used to approximate harmonic sounds in nature include sawtooth waves, square waves and triangle waves.

While a sound may still be referred to as being of a single frequency (for example, a piano striking the A above middle C is said to be playing a note at 440 Hz), the sound perceived by a listener will be colored by all of the sound wave's frequency components and their relative amplitudes, as well as how the sound changes over time (see timbre.) For convenience in this article, however, it is best to think of sound waves as sine waves.

The solar system is the retinue of objects gravitationally bound to our Sun. Traditionally, it is said to consist of nine planets and their 157 (at last count) moons; however a large number of other objects, including asteroids, meteoroids, planetoids and comets orbit the Sun along with them.

The term ‘‘solar system’’ is generally applicable only to our own, with those around other stars referred to as planetary systems. When talking about a specific star's planetary system, it is usual to shorten it to "the <name> system" (e.g. "the Alpha Centauri system" or "the 51 Pegasi system").

The Sun (astronomical symbol ☉) is a spectral class G2 star that contains 99.86% of the system's mass. Its two largest orbiting bodies, Jupiter and Saturn, account for 91% of the remainder (The Oort Cloud could hold a substantial percentage as well, but as yet its existence is unconfirmed).

In broad terms, the charted regions of our solar system consist of the Sun, eight bodies in relatively unique orbits (commonly called planets or major planets) and two belts of smaller objects (which can be called minor planets, planetoids, meteoroids, planetesimals or, in the case of Pluto, planets). Objects in orbit round the Sun all lie within the same shallow plane, called the ecliptic, and all orbit in the same direction. Many are in turn orbited by moons, and the largest are encircled by planetary rings of dust and other particles.

The major planets are, in order, Mercury (☿), Venus (♀), Earth (♁), Mars (♂), Jupiter (♃), Saturn (♄), Uranus (♅/ ), Neptune (♆), and Pluto (♇), though Pluto's status has been thrown into question by the discovery of 2003UB313 (see below). All planets except Earth are named after gods and goddesses from Greco-Roman mythology (however, Earth is also called Terra, which is the name of the Roman goddess of earth).

Distances within the solar system are measured most often in astronomical units, or AU. 1 AU is the distance between the Earth and the Sun, or roughly 150 million kilometers. Pluto is roughly 38 AU from the Sun, while Jupiter lies at roughly 5.2 AU. For very large distances within the solar system, such as regions beyond Pluto or the orbital circumferences of planets, the terameter (Tm, one billion kilometers) is sometimes used.

Despite the fact that many diagrams (like the at the top of this article), for practicality's sake, represent the solar system as having each orbit the same distance apart, in actuality the orbits are largely arranged geometrically, that is, each is roughly double the distance from the Sun as the one before it. Venus’s distance from the Sun is roughly double that of Mercury, Earth’s distance is roughly double that of Venus, Mars’s double that of Earth and so on.

Origin and evolution of the solar system

The current hypothesis of solar system formation is the nebular hypothesis, first proposed in 1755 by Immanuel Kant. It states the solar system was formed from a gaseous cloud called a solar nebula. It had a diameter of 100AU and was 2-3 times the mass of the Sun. Over time, the nebula began to collapse, possiby due to disturbance by a nearby supernova. A supernova occurs when a massive star ceases to generate fusion energy in its core, and collapses inward under the force of its own gravity. This explosion sent waves into space, which squeezed the nebula, drawing more and more matter inward until gravitational forces overcame its internal gas pressure and it also began to collapse. As the nebula collapsed, it decreased in size, which in turn caused it to spin faster to conserve angular momentum. And as the competing forces associated with gravity, gas pressure, and rotation acted on it, the contracting nebula began to flatten into a spinning pancake shape with a bulge at the center.

When the nebula further condensed, a protostar was formed in the middle. This system was heated by the friction of the rocks colliding into each other. Lighter elements such as hydrogen and helium were pushed out of the centre and into the edges of the disc, whilst heavier elements such as those forming dust and rocks were concentrated into the centre. These heavier elements clumped together to form planetisimals and protoplanets. In the outer regions of this solar nebula, ice and volatile gases were able to survive, and as a result, the inner planets are rocky and the outer planets were massive enough to attract large amounts of lighter gases, such as hydrogen and helium.

After 100 million years, the pressures and densities of hydrogen in the centre of the collapsed nebula became great enough for the protosun to sustain thermonuclear fusion reactions. As a result of this, hydrogen was converted to helium, and a great amount of heat was released.

 1He + neutrinos + energy)à(4H

During that time, the protostar turned into the Sun and the protoplanets and planetisimals were transformed into planets. All of the planets formed in a relatively short time of a few million years.

Regions of the solar system

According to their location, the objects in the solar system are divided into three zones: Zone I or the inner solar system, including terrestrial planets and the Main belt of asteroids; Zone II, including the giant planets, their satellites and the centaurs, and Zone III, or the outer solar system, comprises the area of the Trans-Neptunian objects including the Kuiper Belt, the Oort cloud, and the vast region in between.

Interplanetary medium

The environment in which the solar system resides is called the interplanetary medium. The Sun radiates a continuous stream of charged particles, a plasma known as solar wind, which forms a very tenuous “atmosphere” (the heliosphere), permeating the interplanetary medium in all directions for at least ten billion miles into space. Small quantities of dust are also present in the interplanetary medium and are responsible for the phenomenon of zodiacal light. Some of the dust is likely interstellar dust from outside the solar system.

The inner planets

The four inner or terrestrial planets are characterised by their dense, rocky makeup. They formed in the hotter regions close to the Sun, where lighter and more volatile materials evaporated, leaving only those with high melting points, such as silicates, which form the planets' solid crusts and semi-liquid mantles, and iron, which forms their cores. All have impact craters and many possess tectonic surface features, such as rift valleys and volcanoes. The four inner planets are:

• Mercury (0.39 AU ftom the Sun): The closest planet to the Sun is also the smallest and most atypical of the inner planets, having no atmosphere and, to date, no observed geological activity save that produced by impacts. Its relatively large iron core suggests that it was once a much larger world whose outer mantle was sheared off in early formation by the Sun’s gravity.

• Venus (0.72 AU): The first truly terrestrial planet, Venus, like the Earth, possesses a thick silicate mantle around an iron core, as well as a substantial atmosphere and evidence of onetime internal geological activity, such as volcanoes. Its atmosphere is 90 times as dense as Earth’s, however, and composed overwhelmingly of carbon dioxide and sulfuric acid.

• Earth/Moon (1 AU): The largest of the inner planets, Earth is also the only one to demonstrate unequivocal evidence of ongoing geological activity. Its liquid hydrosphere, unique among the terrestrials, is probably the reason why Earth is also the only planet where multi-plate tectonics has been observed, since water acts as a lubricant for subduction. Its atmosphere is radically different from the other terrestrials, having been altered by the presence of life to contain 21 percent free oxygen. Its satellite, the Moon, is sometimes considered a terrestrial planet in a co-orbit with its partner, since its orbit around the Sun never actually loops back on itself when observed from above. The Moon possesses many of the features in common with other terrestrial planets, though it lacks an iron core.

• Mars (1.5 AU): Smaller than the Earth or Venus, Mars possesses a tenuous atmosphere of carbon dioxide. Its surface, peppered with vast volcanoes and rift valleys such as Valles Marineris, shows that it was once geologically active and recent evidence suggests it may have continued to be so until very recently. Mars possesses two tiny moons thought to be captured asteroids.

The asteroid belt

Asteroids are objects smaller than planets that mostly occupy the orbit between Mars and Jupiter, between 2.3 and 3.3 AU from the Sun, and are composed in significant part of non-volatile minerals. The main belt contains tens of thousands (possibly millions) over 1km across, though they can be as small as dust. Despite their large numbers, the total mass of the main asteroid belt is unlikely to be more than a thousandth that of the Earth. Asteroids with a diameter of less than 50m are called meteoroids. The largest asteroid, Ceres, has a diameter of roughly 1000 km; large enough to be spherical, which would make it a planet by some definitions of the word. The asteroids are thought to be the remnants of a small terrestrial planet that failed to coalesce due to the gravitational interference of Jupiter. They are subdivided into asteroid groups and families based on their specific orbital characteristics. Asteroid moons are asteroids that orbit larger asteroids. They are not as clearly distinguished as planetary moons, sometimes being almost as large as their partners.

Trojan asteroids are located in either of Jupiter's L₄ or L₅ points, though the term is also sometimes used for asteroids in any other planetary Lagrange point as well.

The outer planets

The four outer planets, or gas giants, are so large they collectively make up 99 percent of the mass known to orbit the Sun. Their large sizes and distance from the Sun meant they could hold on to much of the hydrogen and helium too light for the smaller and hotter terrestrial planets to retain.

• Jupiter (5.2 AU), at 318 Earth masses, is 2.5 times the mass of all the other planets put together. Its composition of largely hydrogen and helium is not very different from that of the Sun. Three of its 63 satellites, Ganymede, Io and Europa, share elements in common with the terrestrial planets, such as volcanism and internal heating. Jupiter has a faint, smoky ring.

• Saturn (9.5 AU), famous for its extensive ring system, shares many qualities in common with Jupiter, including its atmospheric composition, though it is far less massive, being only 95 Earth masses. Two of its 49 moons, Titan and Enceladus, show signs of geological activity, though they are largely made of ice. Titan is the only satellite in the solar system with a substantial atmosphere.

• Uranus (19.6 AU) and Neptune (30 AU), while having many characteristics in common with the other gas giants, are nonetheless more similar to each other than they are to Jupiter or Saturn. They are both substantially smaller, being only 14 and 17 Earth masses, respectively. Their atmospheres contain a smaller percentage of hydrogen and helium, and a higher percentage of “ices”, such as water, ammonia and methane. For this reason some astronomers suggested that they belong in their own category, “Uranian planets,” or “ice giants.” Both planets possess dark, insubstantial ring systems. Neptune’s largest moon Triton is geologically active.

What is a Weblog or Blog ?

A weblog or blog (derived from web + log) is a web-based publication consisting primarily of periodic articles (normally, but not always, in reverse chronological order). Although most early blogs were manually updated, tools to automate the maintenance of such sites made them accessible to a much larger population, and the use of some sort of browser-based software is now a typical aspect of "blogging."

Blogs range in scope from individual diaries to arms of political campaigns, media programs, and corporations. They range in scale from the writings of one occasional author (known as a blogger), to the collaboration of a large community of writers. Many weblogs enable visitors to leave public comments, which can lead to a community of readers centered around the blog; others are non-interactive. The totality of weblogs or blog-related websites is often called the blogosphere. When a large amount of activity, information and opinion erupts around a particular subject or controversy in the blogosphere, it is sometimes called a blogstorm or blog swarm.

The tools for editing, organizing, and publishing weblogs are variously referred to as "content management systems," "publishing platforms," "weblog software," and simply "blogware."

Blogging, like any hobby, has developed something of a specialised vocabulary. The following is an attempt to explain a few of the more common phrases and words, including etymologies when not obvious. For a complete list, see List of Blogging Terms.

Audioblog

A blog where the posts consist mainly of voice recordings sent by mobile phone, sometimes with some short text message added for metadata purposes. (cf. podcasting)

Blog feed

The XML-based file in which the blog hosting software places a machine-readable version of the blog so that it may be "syndicated" for further distribution on the web. Formats such as RSS and Atom are used to structure the XML file.

Blogroll

A list of blogs. Usually a blogger features a list of his favorite blogs in the sidebar of his blog. These lists can be made dynamic using services like BlogRolling.

Blog site

The web location (URL) of a blog, which may be either a dedicated domain, a sub-domain, or embedded within a web site.

Blogsite

Sometimes confused with a simple blog or blog site, but a blogsite is a web site which combines blog feeds from a variety of sources, as well as non-blog sources, and adds significant value over the raw blog feeds.

Dark Blog

A non-public blog (e.g. behind a firewall)

Moblog

A portmanteau of "mobile" and "blog". A blog featuring posts sent mainly by mobile phone, using SMS or MMS messages. They are often photoblogs.

Permalink

Permanent link. The unique URL of a single post. Use this when you want to link to a post somewhere.

Ping

The alert in the TrackBack system that notifies the original poster of a blog post when someone else writes an entry concerning the original post.

TrackBack

A system that allows a blogger to see who has seen the original post and has written another entry concerning it. The system works by sending a 'ping' between the blogs, and therefore providing the alert.

Troll

A commenter whose sole purpose is to attack the views expressed on a blog, for example, a liberal going to a conservative blog, or vice versa. Many trolls will leave their remarks on multiple posts and continue to visit the blog, sparking spirited debate amongst the blog's regular readers. Trolls' verbosity can range from eloquent to crass, although most trolls probably fall into the latter category

Looking back at the history of Karnataka here are some of the Rulers & Administrators who have structured Bangalore & Karnataka…

The Rulers

Kempegowdas
The most prominent among the feudatories of Vijayanagar from this district were the Bangalore-Magadi rulers, popularly known as the Kempegowdas They were originally the Yelahanka Nadaprabhus, later having Bangalore as their headquarters to Magadi and Savanadurga from where they ruled till their overthrow by the Mysore dynasty in 1728.

Kempegowda I(c 1510-70) is responsible for building the modern city of Bangalore(c1537), erecting a mud fort here to the north of the now existing fort which covered the area of Avenue Road and its surroundings. This he is said to have done at the instructions of Emperor Achutaraya and it is he who raised the Basavanagudi (temple) and expanded the Gavigangadhara and Someshwara temples. He is also credited with the construction of the Sampangi tank, the Kempambudhi and the Dharmambudhi tanks in Bangalore. A statue of his is found at the Gangadhara temple at Shivaganga, though the inscription on it is dated 1609, perhaps a posthumous writing.

Kempegowda II was responsible in erecting the four towers at the four cardinal points at Bangalore. He expanded the Ulsoor Someshwara temple and also built the Karanji tank of the Basavanagudi area.He and his father were responsible for the development of modern Bangalore as a town. They invited traders and artisans, especially weavers from outside to come and settle down in Bangalore.

Bijapurs & Marathas
Karnataka was connected politically with the Marathas in the 17th and 18th centuries. Their activities began in Karnataka when Ranadulla Khan, the Bijapur general captured Bangalore in 1637. Shahji Bhosle who had accompanied Ranadulla Khan was given the jagir of Bangalore. Shahji ruled like a King, built a palace in Bangalore and set up an administration. Though Shahji was loyal to Bijapur, his son Shivaji revolted in Maharashtra and challenged the authority of the Sultan of Bijapur. Enraged by this, Shahji was imprisoned and later released by the Sultan of Bijapur. Shahji remained loyal to the Sultan of Bijapur till his death in 1664. His son Ekoji succeeded to the Bangalore jagir. In the meanwhile, Shivaji had started his activities against Bijapur and conquered the whole of Bangalore jagir. Shivaji had to struggle to retain the territory till his death in 1680. Later Peshwa Baji Rao conducted two campaigns in Karnataka and Tribute was collected from Mysore. However after the defeat of Marathas in 1761, their activities came to an end when Tipu Sultan became the ruler of Mysore.

Mysore Dynasty
Chikkadevaraja Wodeyar, grandson of Bola Chamaraja Wodeyar, nephew and successor of Devaraja Wodeyar, was the most distinguished among the Mysore Rajas. He succeeded to the throne in 1673 at the age of 28 years. He made several successful expeditions against Ikkeri, Bijapur and defeated Shivaji, and added further more to his Kingdom. He accquired Bangalore by purchase and sent an embassy to the court of Aurangzeb. By 1700 Chikkadevaraja Wodeyar was at the height of his power.He divided the business of the Government into 18 Kacheris or Department. He was also a great administrator and a patron of literature. An ardent Vaisnava, he gave prominence to the Vagramukuta festival in Melkote. He followed the Veerasaiva tenets as well. His reign witnessed unrivalled literary activity. There flourished in his court great poets, and poetesses like Tirumalaraya, Singaraya, Honnamma and Girijamma. He built a pond at Sravanabelagola for the use of Jain pilgrims. During his reign Srirangapatna became a flourishing city and a political centre of gravity.

Hyder Ali
Hyder, an ordinary soldier in the Mysore Army was destined to become supreme in the state in 1761 by usurping authority from the Raja. He was born at Budikote near Kolar in 1721 A.D. Hyder was a born soldier. He revealed his talents as a soldier in the siege of Devanahalli. In 1752 he accompanied the Mysore forces and fought the French and Chanda Sahib. He was placed in charge of the Dindigal fort where he increased his troops and organized a artillery force. Hyder drove out the Martha forces and quelled the mutiny of the Mysore troops. Hyder was hailed in the open Durbar as Fateh Hyder Bahadur. In 1771, when the Marathas invaded Hyder's territories, the English refused to help him. Being angry, Hyder subdued Coorg and Chitradurga and in 1779 he joined in a confederacy against English. Thus broke out the second Anglo Mysore war. But in the midst of the war Hyder died. Hyder came to fame by war. He was always engaged in war and died in war. By his conquests he extended the territories of Mysore and doubled its size.He never allowed his religion to interfere in state matters. Hyder was a warrior, administrator and statesman.

Tipu Sultan
Tipu was one of the greatest national heroes that Karnataka produced. He assumed the sovereignty of Mysore on the death of his father, Hyder Ali. Born in 1753 at Devanahalli., the place where Hyder distinguished himself, he was named after a Moslem saint of Arcot, for whom Hyder had a special veneration. Tipu accompanied his father in 1766 to Mangalore and displayed his dash and courage in attacking the Paleyagar of Balam. He helped his father in capturing the forts of Tirapatur and Vaniambadi. While he was engaged against the British, Hyder Ali passed away. Tipu assumed the control of the affairs and sat on the throne on December 29, 1782. Tipu has left a deep impression on the history of Karnataka. He instilled in the minds of the people the spirit of patriotism and love for their country. He was a good administrator. He gave encouragement to Agriculture. He established a highly centralized administration manned by seven departments. Tipu also found time to patronize art. To his period belongs the Darya-daulat Bagh palace, Masjid-e-Ala at Srirangapatna and the summer palace at Bangalore. It is the opinion of scholars that Tipu's administration was better and his people happier than in other states. This brief survey of his achievements shows that Tipu was a remarkable personality. When Tipu Sultan died in the 4th Mysore war in 1799, the British gave the kingdom, including Bangalore back to Krishna Raja Wodeyar III. The British Resident stayed in Bangalore. In 1881, the British returned the city to the Wodeyars. Diwans like Mirza Ismail, and Sir M Vishweshwarayya were the pioneers to help Bangalore attain its modern outlook.

The Administrators

The Dewans
Krishnaraja Wodeyar III sent many representations to various men in power and even sent Dr.Campbell, his family surgeon to England in 1864 to represent his case for restoration of power. The Raja succeeded in creating a lobby in his favor even in London. The British Government took a decision to restore the adopted son to the throne. The Raja died in 1868 and his adopted son Chamarajendra Wodeyar X was crowned in March 1881. After the Rendition many administrative changes were introduced. The post of the Commissioner was abolished and a British Resident was appointed at the Mysore Court. The post of Dewan was created and he was to be the head of the administrative machinery.

Dewan Rangacharulu
C.Rangacharulu was appointed as the first Dewan of Mysore after the Rendition. The Dewan introduced great economy in administration, floated public loans and undertook public works to provide jobs to the unemployed peasant. Bangalore-Mysore Railway line was completed in 1882 with a total cost of Rs.43 lakhs. The Bangalore Palace building constructed by an officer, was purchased by royalty in 1882.

Sheshadri Iyer
Sir K.Sheshadri Iyer succeeded as the Dewan of Mysore after the death of Rangacharulu in 1883. He was a wise and talented administrator and was responsible for implementing many schemes aimed at the progress of the state. It was during his time that gold mining was started in Kolar in 1886. Sheshadri Iyer undertook extensive plantation program, especially of coffee. The Sivasamudra hydro-electric project was implemented by him in 1899-1900. Electricity was supplied to the K.G.F in 1902 and to Bangalore in 1905.

Dewan Visveswaraya
Sir M.Visveswaraya became the Dewan in 1912 and his Dewanship is especially for the development in the field of Industries. He did much for the Industrialization of Mysore. A number of projects and Industries were implemented during Sir M.Visveswaraya's Dewanship. They included the starting of the Krishnarajasagara Dam at Kannambadi, the founding of the Iron Works at Bhadravathi and the Mysore Bank with Bangalore as the headquarters, Sandal Oil Factory at Mysore and several other Projects.The Mysore Chamber of Commerce was also inaugurated in 1916.
It was Visveswaraya's desire to improve the conditions in the country so as to make it economically prosperous, scientifically progressive, industrially sound and well advanced. He was the true architect of modern Mysore and by his indefatigable work he made Mysore a model state.

Dewan Mirza Ismail
Sir Mirza Ismail was appointed Dewan of Mysore in 1926 and the period of his administration was an eventful one. He built the superstructure on the foundations laid by Sir M.Visveswaraya. His period saw the state making substantial progress in the fields of Industries both in the private and public sectors. Among them mention may be made of cement factory, the Chemical and Fertilizers factory and Sugar mills. He was an able administrator and set an inspiring example to the officials by undertaking extensive tours and personally looking to the grievances of the people. During his time the Medical College was established in Mysore. He was also responsible for the laying of Brindavan Gardens near Krishnarajasagar.